Chapter 12: Magnetic Effects of Electric Current

Important questions — the ones the board asked most (20)

1. Q1Long answer5 marksAsked: 2026

   Attempt either (a) or (b) : (a) (i) What is a solenoid ? Draw a diagram showing the magnetic field pattern due to a current-carrying solenoid (inside and outside). (ii) Name any two factors on which the magnitude of the magnetic field due to a current-carrying solenoid depends. (iii) A current-carrying solenoid is stretched and converted into a straight wire carrying current. Draw a diagram showing the magnetic field pattern around it and mark the direction of the magnetic field. OR (b) (i) With the help of a diagram, show that a current-carrying conductor placed in an external magnetic field, experiences a force. Indicate the direction of the field, current and force clearly. (ii) The diagram given below shows an electron moving in a uniform magnetic field. (I) What will be the direction of the force acting on the electron ? (II) What will happen to the direction of the force acting on the electron, if the direction of the magnetic field as well as the direction of motion of the electron, both are reversed ?

   

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   Model answer · Fleming's left hand rule, Right-Hand Thumb Rule

   1. 1.(a)(i) A solenoid is a coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder. OR (b)(i) Diagram: a small aluminium rod AB is suspended horizontally between the poles of a horseshoe magnet and connected in series with a battery, a key and a rheostat.1 mark
   2. 2.(a)(i) Diagram: inside the solenoid the field lines are parallel straight lines (uniform field); outside, the lines come out of one end (N) and go into the other end (S), like the field of a bar magnet; arrows mark the direction. OR (b)(i) When the key is closed and current flows through AB, the rod is displaced (moves); this shows that a force acts on the current-carrying conductor placed in the magnetic field.1 mark
   3. 3.(a)(ii) The magnetic field of a solenoid depends on (1) the number of turns in the coil and (2) the strength of the current flowing in it (also the nature of the core material). OR (b)(i) In the diagram, mark the field from N to S, the current along the rod and the force (displacement) at right angles to both, as given by Fleming's left-hand rule.1 mark
   4. 4.(a)(iii) Diagram: the field lines around the straight current-carrying wire are concentric circles with the wire at their centre, drawn closer together near the wire. OR (b)(ii)(I) The electron moves upward, so the conventional current is downward; the field is towards the left. By Fleming's left-hand rule, the force on the electron is perpendicular to the plane of the paper, directed into the paper.1 mark
   5. 5.(a)(iii) Arrows on the circles show the direction of the field given by the right-hand thumb rule: if the thumb points along the current, the curled fingers give the field direction (e.g. current upward gives anticlockwise circles seen from above). OR (b)(ii)(II) If both the field and the direction of motion of the electron are reversed, the direction of the force does not change; it stays into the plane of the paper, because the two reversals cancel each other.1 mark

   Diagram: Diagram 1 (Fleming's left hand rule): a horizontal aluminium rod AB between the poles of a horse-shoe magnet (N below, S above), with arrows labelled \"magnetic field\" (upwards), \"current\" (B to A) and \"force\" (perpendicular to both, towards the left). Diagram 2, drawn separately (Right-Hand Thumb Rule): a straight vertical wire with an arrow labelled \"current\", and concentric circles around it with arrows labelled \"magnetic field lines\".

   Marks split as in the board’s published marking scheme

2. Q2Long answer5 marksAsked: 2026

   Attempt either (a) or (b) : (a) (i) Write the name and statement of the rule used to determine the direction of the : (I) force experienced by a straight current-carrying conductor placed in a uniform magnetic field perpendicular to the field. (II) magnetic field produced around a straight conductor carrying electric current. (ii) Differentiate between the magnetic field due to a bar magnet and the magnetic field due to a current-carrying solenoid. OR (b) (i) With the help of a diagram, describe an activity in brief to show that a current-carrying straight conductor produces a magnetic field around it. (ii) Two straight current-carrying conductors (A) and (B) are shown in the figures below : (I) Mark the direction of the magnetic fields around these current-carrying conductors (A) and (B). (II) Compare the strengths of magnetic fields produced (1) at points P and Q and (2) at points Q and R due to these current-carrying conductors, qualitatively.

   

   Medha Ma’am

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   Model answer · Fleming's rule, right-hand rule

   1. 1.(a)(i)(I) Fleming's left-hand rule: stretch the forefinger, middle finger and thumb of the left hand mutually perpendicular; with the forefinger along the magnetic field and the middle finger along the current, the thumb gives the direction of the force. OR (b)(i) Activity: pass a straight wire vertically through a cardboard, connect it to a battery, key and rheostat, sprinkle iron filings on the cardboard (or place a compass) and pass the current.1.5 marks
   2. 2.(II) Right-hand thumb rule: hold the conductor in the right hand with the thumb along the current; the curled fingers give the direction of the magnetic field lines. OR On tapping, the filings form concentric circles around the wire, showing the magnetic field; (ii)(I) the field directions around A and B are marked on concentric circles by the right-hand thumb rule.1.5 marks
   3. 3.(a)(ii) A bar magnet's field is permanent and cannot be changed; a solenoid's field depends on the current and vanishes when the current is switched off. OR (ii)(II)(1) Of P and Q, the point nearer its conductor has the stronger field, as the field weakens with distance.1 mark
   4. 4.Inside a solenoid the field lines are parallel straight lines (a uniform field), while a bar magnet's field is not uniform; a solenoid's field can be made stronger with more turns or a soft-iron core. OR (2) Q and R are compared the same way: the nearer point has the stronger field, and points at equal distances from equal currents have equal fields.1 mark

   Marks split from a structure derived from past papers (checked twice); not CBSE’s official scheme

3. Q3Long answer5 marksAsked: 2025

   (A) (i) Draw the pattern of the magnetic field lines for the two parallel straight conductors carrying current of same magnitude ‘I’ in opposite directions as shown. Show the direction of magnetic field at a point O which is equidistant from the two conductors. (Consider that the conductors are inserted normal to the plane of a rectangular cardboard.) (ii) In our houses we receive A.C. electric power of 220 V. In electric iron or electric heater cables having three wires with insulation of three different colours – red, black and green are used to draw current from the mains. (a) What are these three different wires called? Name them colourwise. (b) What is the potential difference between the red wire and the black wire? (c) What is the role of the wire with green insulation in case of accidental leakage of electric current to the metallic body of an electrical appliance? OR (B) (i) By using the given experimental set-up. How can it be shown that : (a) a force is exerted on the current-carrying conductor AB when it is placed in a magnetic field. (b) the direction of force can be reversed in two ways. (ii) When will the magnitude of the force be highest? (iii) State Fleming’s left hand rule.

   

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   Watch it on the board · 185 s

   Model answer · Field lines, domestic circuit wires

   1. 1.Pattern: the magnetic field lines around each straight conductor are a series of concentric circles centred on that conductor. They lie in the plane of the cardboard, and the circles are closer together near each wire. The direction of the circles is given by the right-hand rule. Because the currents flow in opposite directions, the circles around one conductor go anticlockwise and the circles around the other go clockwise. In the region between the two conductors, the field lines of both wires point the same way, so the field lines crowd together there.1 mark
   2. 2.Direction at O: take the left conductor carrying current I out of the cardboard and the right conductor carrying current I into it. At O, which is equidistant from both, the magnetic fields due to the two conductors point in the same direction. Both point upward in the plane of the cardboard, perpendicular to the line joining the conductors. So the two fields add up, and the net magnetic field at O is in this direction.1 mark
   3. 3.(ii) (a) Red wire: live wire (or positive).0.5 marks
   4. 4.Black wire: neutral wire (or negative).0.5 marks
   5. 5.Green wire: earth wire. It is connected to a metal plate deep in the earth.0.5 marks
   6. 6.(b) The potential difference between the red (live) wire and the black (neutral) wire is 220 V.0.5 marks
   7. 7.(c) The earth wire is used as a safety measure. If current leaks to the metallic body of the appliance, the earth wire keeps the body's potential equal to that of the earth. So the user does not get a severe electric shock.1 mark

   Diagram: Draw two dots on a rectangular cardboard, one marked ⊙ (current I out of the cardboard) and one marked ⊗ (current I into the cardboard). Around each dot draw concentric circles with arrows: anticlockwise around ⊙ and clockwise around ⊗. Mark the point O midway between them with an arrow showing the magnetic field there, perpendicular to the line joining the conductors. Label the field lines, the current I in each conductor and the point O.

   • Put arrows on the concentric circles in the diagram, in opposite senses around the two conductors, and draw one clear arrow at O.
   • Write the full name with each colour: "Red wire: live wire", "Black wire: neutral wire", "Green wire: earth wire".
   • For the green wire, write that it keeps the metallic body "equal to that of the earth" so that the user does not get a severe electric shock.

   Marks split as in the board’s published marking scheme

4. Q4Long answer5 marksAsked: 2025

   (A) (i) Draw the pattern of the magnetic field lines for the two parallel straight conductors carrying current of same magnitude 'I' in opposite directions as shown. Show the direction of magnetic field at a point O which is equidistant from the two conductors. (Consider that the conductors are inserted normal to the plane of a rectangular cardboard.) (ii) In our houses we receive A.C. electric power of 220 V. In electric iron or electric heater cables having three wires with insulation of three different colours - red, black and green are used to draw current from the mains. (a) What are these three different wires called? Name them colourwise. (b) What is the potential difference between the red wire and the black wire? (c) What is the role of the wire with green insulation in case of accidental leakage of electric current to the metallic body of an electrical appliance? OR (B) (i) By using the given experimental set-up. How can it be shown that : (a) a force is exerted on the current-carrying conductor AB when it is placed in a magnetic field. (b) the direction of force can be reversed in two ways. (ii) When will the magnitude of the force be highest? (iii) State Fleming's left hand rule.

5. Q5Long answer5 marksAsked: 2025

   (A) (i) Draw the pattern of the magnetic field lines for the two parallel straight conductors carrying current of same magnitude 'I' in opposite directions as shown. Show the direction of magnetic field at a point O which is equidistant from the two conductors. (Consider that the conductors are inserted normal to the plane of a rectangular cardboard.) (ii) In our houses we receive A.C. electric power of 220 V. In electric iron or electric heater cables having three wires with insulation of three different colours – red, black and green are used to draw current from the mains. (a) What are these three different wires called? Name them colourwise. (b) What is the potential difference between the red wire and the black wire? (c) What is the role of the wire with green insulation in case of accidental leakage of electric current to the metallic body of an electrical appliance? OR (B) (i) By using the given experimental set-up. How can it be shown that : (a) a force is exerted on the current-carrying conductor AB when it is placed in a magnetic field. (b) the direction of force can be reversed in two ways. (ii) When will the magnitude of the force be highest? (iii) State Fleming's left hand rule.

   How the model answer begins

   1. (A)(i) On the cardboard the field lines are concentric circles around each conductor; since the currents are opposite, the circles around one conductor run clockwise and around the other anticlockwise, and between the…

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6. Q6Long answer5 marksAsked: 2025

   36. (a) What are magnetic field lines ? How is the direction of magnetic field at a point determined ? Draw the pattern of magnetic field lines of the magnetic field produced by a current carrying circular loop. Mark on it the direction of (i) current and (ii) magnetic field lines. Name the two factors on which the magnitude of the magnetic field due to a current carrying coil depends. OR (b) Why can't two magnetic field lines cross each other ? Draw magnetic field lines showing the direction of the magnetic field due to a current carrying long straight solenoid. State the conclusion which can be drawn from the pattern of magnetic field lines inside the solenoid. Name any two factors on which the magnitude of the magnetic field due to this solenoid depends.

7. Q7Long answer5 marksAsked: 2025

   36. (a) Study the following electric circuit diagram and answer the questions that follow : (i) What does the circuit diagram shows ? (ii) What will happen if the direction of current is reversed ? Justify your answer giving circuit diagram. (b) Name and state the rule to determine the direction of magnetic field associated with a straight current carrying conductor. OR (a) Draw the pattern of magnetic field lines of (i) a bar magnet (ii) a current carrying solenoid List two distinguishing features between the two magnetic fields.

   How the model answer begins

   1. (a)(i) The circuit shows that a current-carrying straight wire produces a magnetic field around it — the compass needle placed near it is deflected. (ii) If the current is reversed, the needle is deflected the opposite…

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8. Q8Long answer5 marksAsked: 2026

   Attempt either (a) or (b) : (a) (i) State the rule which gives the direction of force acting on a current-carrying conductor placed in a magnetic field. (ii) What is a fuse ? Why is it called a safety device ? (iii) Why are electrical appliances with metallic bodies connected to the mains through a three-pin plug, whereas an electric bulb is connected with a two-pin plug ? (iv) [Figure showing magnetic field lines and a conductor AB with current direction] What will be the direction of force experienced by the conductor AB due to the magnetic field, when current flows in the direction shown ? Name the law you applied to find the direction. OR (b) (i) Draw the pattern of magnetic field lines through and around a current-carrying circular loop. (ii) State the rule to find out the direction of the magnetic field inside and around the circular loop. (iii) Give reasons : (I) Why should a burnt-out fuse be replaced by another fuse of identical rating only, in an electric circuit ? (II) Why is soft iron-core used in making an electromagnet ?

   How the model answer begins

   1. (a) (i) Fleming's left-hand rule gives the direction of the force on a current-carrying conductor placed in a magnetic field. Stretch the thumb, forefinger and middle finger of your left hand so that they are mutually…

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9. Q9Long answer5 marksAsked: 2026

   (a) (i) State the rules to determine the following : (I) Direction of magnetic field produced around a current-carrying straight conductor. (II) Direction of force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it. (ii) (I) Draw the magnetic field lines due to a current-carrying solenoid. (II) Three points A, B and C are marked in the above given diagram of the current-carrying solenoid. Out of the three points A, B and C, at which point is the magnetic field strength maximum and at which point is it minimum ? OR (b) (i) (I) In the given circuit diagram, a battery B, a key K, a resistance R and a thick copper wire XY are connected in series and a compass is placed near the wire. What is the purpose of this arrangement ? (II) What conclusion do you draw from it ? (ii) Give reasons : (I) There is either a convergence or a divergence of magnetic field lines near the ends of a current-carrying straight solenoid. (II) The current-carrying solenoid, when suspended freely, aligns along a particular direction. (III) The burnt-out fuse should be replaced by another fuse of identical rating.

   How the model answer begins

   1. (a)(i)(I) Right-hand thumb rule: hold the conductor in the right hand with the thumb along the current; the fingers wrap around it in the direction of the magnetic field. OR (b)(i)(I) The set-up shows that a…

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10. Q10Long answer5 marksAsked: 2026

    (A) (i) Draw a diagram showing the magnetic field lines around a bar magnet. Write any two characteristics of magnetic field lines. (ii) Write the statement of Right hand thumb rule. (iii) The concentric circles representing the magnetic field around a current carrying straight wire become larger and larger as we move away from the wire. How does magnetic field change on these concentric circles ? OR (B) (i) Draw a diagram, showing the magnetic field lines in and around the current carrying solenoid. Write any two salient features of these lines. (ii) What is an electromagnet and how is it made ?

    How the model answer begins

    1. (A)(i) Diagram: closed field lines around a bar magnet, with arrows from the north pole to the south pole outside, crowded near the poles. OR (B)(i) Diagram: a current-carrying solenoid with parallel straight lines…

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11. Q11Very short answer5 marksAsked: 2025

    (iii) State Fleming's left hand rule. Using this rule, determine the direction of force applied on an electron entering a uniform magnetic field as shown in the figure. OR (b) (i) Define the term solenoid. Draw the pattern of the magnetic field lines in and around a current carrying straight solenoid. Mark on the pattern the (i) direction of current, (ii) direction of field lines near the ends of the solenoid, and (iii) region where the magnetic field is uniform. (ii) How would you make an electromagnet using a current carrying solenoid?

    How the model answer begins

    1. (a) Fleming's left-hand rule: stretch the forefinger, middle finger and thumb of the left hand mutually perpendicular. OR (b)(i) A solenoid is a coil of many circular turns of insulated copper wire wrapped closely in…

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12. Q12Long answer5 marksAsked: 2025

    (a) The given figure shows the current passing through the straight conductor XY. (i) Copy the diagram and draw the magnetic field lines when current flows from conductor X to Y. (ii) Name and state the rule used in determining the direction of the magnetic field lines in the situation given above. (iii) State Fleming's left-hand rule. Using this rule, determine the direction of force on an electron entering a uniform magnetic field as shown in the diagram. OR (b) (i) Define a solenoid. Draw the pattern of magnetic field lines produced inside and around a straight current-carrying solenoid. Mark on this pattern (i) the direction of current, (ii) the direction of magnetic field lines near the ends of the solenoid and (iii) the region of uniform magnetic field. (ii) How will you use a current-carrying solenoid to make an electromagnet?

    How the model answer begins

    1. (i) When current flows through the straight conductor from X (top) to Y (bottom), the magnetic field lines are concentric circles centred on the wire, in a plane perpendicular to it. Seen from above, the arrows on the…

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13. Q13Long answer5 marksAsked: 2025

    34. (a) The given figure shows the current passing through the straight conductor XY. (i) Copy the diagram and draw the magnetic field lines when current flows from conductor X to Y. (ii) Name and state the rule used in determining the direction of the magnetic field lines in the situation given above. (iii) State Fleming's left hand rule. Using this rule, determine the direction of force applied on an electron entering a uniform magnetic field as shown in the figure. OR (b) (i) Define the term solenoid. Draw the pattern of the magnetic field lines in and around a current carrying straight solenoid. Mark on the pattern the (i) direction of current, (ii) direction of field lines near the ends of the solenoid, and (iii) region where the magnetic field is uniform. (ii) How would you make an electromagnet using a current carrying solenoid ?

    How the model answer begins

    1. (a) (i) The magnetic field lines around the straight conductor XY are concentric circles centred on the wire. They lie in a plane perpendicular to the conductor. The arrows on the circles show the direction of the field…

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14. Q14Case-based4 marksAsked: 2025

    In our homes, we receive the supply of electric power through a main supply also called mains, either supported through overhead electric poles or by underground cables. In our country the potential difference between the two wires (live wire and neutral wire) of this supply is 220 V. (a) Write the colours of the insulation covers of the line wires through which supply comes to our homes. (b) What should the current rating of the electric circuit (220 V) so that an electric iron of 1 kW power rating can be operated ? (c) (i) What is the function of the earth wire ? State the advantage of the earth wire in domestic electric appliances such as electric iron. OR (c) (ii) List two precautions to be taken to avoid electrical accidents. State how these precautions prevent possible damage to the circuit/appliance.

    How the model answer begins

    1. (a) The live wire has red insulation.

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15. Q15Case-based4 marksAsked: 2025

    39. In order to obtain magnetic field lines around a bar magnet, a student performed an experiment using a magnetic compass and a bar magnet. The magnet was placed on a sheet of white paper fixed on a drawing board. Using magnetic needle he obtained on the paper a pattern of magnetic field lines (as shown below) around the bar magnet. (a) By convention, the field lines emerge from north pole and merge at south pole. Why ? Give reason. (b) State the relationship between strength of the magnetic field and the degree of closeness of the field lines. (c) (A) (i) No two field lines can ever intersect each other. Give reason. (ii) The magnetic field in a given region is uniform. Draw a diagram to represent it. OR (c) (B) Draw the pattern of the magnetic field lines through and around a current carrying solenoid. What does the pattern of field lines inside the solenoid represent ?

    How the model answer begins

    1. (a) The direction of the magnetic field is taken to be the direction in which a north pole of the compass needle moves inside it. Outside a bar magnet, the north pole of the compass needle points away from the north…

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16. Q16Case-based4 marksAsked: 2025

    (a) Paripati ke anusar kshetra rekhayein chumbak ke uttar dhruv se prakat hoti hai aur dakshin dhruv par vilin ho jati hain. Kyon? Karan dijiye. (b) Chumbakiya kshetra ki prabalta aur kshetra rekhayon ki nikatata ki koti ke beech sambandh ka ullekh kijiye. (c) (A) (i) Do kshetra rekhayein ek dusre ka parichhedan kabhi nahi karti hain. Karan dijiye. (ii) Kisi sthan par chumbakiya kshetra ek saman hai. Ise niroopit karne ke liye aarekh khinchiye. OR (c) (B) Kisi dharavahi parinalika ke bheetar aur uske charon or utpann chumbakiya kshetra rekhayon ka pattern aarekhit kijiye. Parinalika ke bheetar chumbakiya kshetra rekhayon ka pattern kya niroopit karta hai?

    How the model answer begins

    1. (a) Field lines emerge from the north pole and merge at the south pole because the direction of the magnetic field is taken to be the direction in which a north pole of the compass needle moves inside it. Near the north…

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17. Q17Short answer3 marksAsked: 2024

    Draw a diagram to show the pattern of magnetic field lines produced by a straight current carrying conductor passing through the centre of a horizontal cardboard sheet, carrying current in the vertically downward direction. In this diagram, show (i) the direction of current in the conductor and (ii) the direction of the corresponding magnetic field lines. State the Right-Hand Thumb Rule and check whether the directions marked by you are in accordance with this rule or not.

18. Q18Short answer3 marksAsked: 2023

    (a) (i) State the rule to determine the direction of force on a current carrying conductor in a magnetic field. (ii) Below are given cases in which an electron enters a magnetic field. Identify the case in which the force on the electron will be (1) maximum and (2) minimum. Give reason for your answers. OR (b) (i) Draw the pattern of magnetic field lines in the following cases : (1) Current carrying solenoid (2) Bar magnet (ii) List two distinguishing features between these two magnetic fields.

    How the model answer begins

    1. (a)(i) Fleming's left-hand rule: stretch the forefinger, middle finger and thumb of the left hand mutually perpendicular; with the forefinger along the field and the middle finger along the current, the thumb gives the…

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19. Q19Short answer3 marksAsked: 2026

    (a) Describe an activity to show that a current carrying conductor, placed in an external magnetic field experiences a force. (b) Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally towards the front wall from the back wall, is deflected by a strong magnetic field to your right side. Find the direction of the magnetic field.

    How the model answer begins

    1. (a) Take a small aluminium rod AB, about 5 cm long. Use two connecting wires to hang it horizontally from a stand. Place a strong horse-shoe magnet so that the rod lies between its two poles, with the north pole…

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20. Q20Short answer3 marksAsked: 2026

    36. (a) The pattern of magnetic field due to a current carrying wire depends upon the shape made by that wire. Justify. (b) A current carrying straight wire AB is shown in the given diagram. Out of X, Y and Z on which point will the strength of magnetic field be maximum and why ?

    How the model answer begins

    1. (a) Around a straight current-carrying wire, the field lines are concentric circles centred on the wire, in a plane perpendicular to it; they get larger, and the field weaker, farther from the wire.

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15 more questions of this chapter, each with its model answer, in the AskMedha app.

Objective questions with the board’s key (10)

1. 1. CBSE 2026

   For Question number 32, two statements are given — one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to this question from the codes (A), (B), (C) and (D) as given below. Assertion (A) : The needle of a compass, kept in an external magnetic field, always aligns itself in the North-South direction of the Earth. Reason (R) : The behaviour of the needle of the compass is similar to the behaviour of a freely suspended bar magnet.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false.
   • (D) Assertion (A) is false, but Reason (R) is true. ✓

   Answer: (D)

2. 2. CBSE 2026

   Assertion (A) : The needle of a compass, kept in an external magnetic field, always aligns itself in the North-South direction of the Earth. Reason (R) : The behaviour of the needle of the compass is similar to the behaviour of a freely suspended bar magnet.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false.
   • (D) Assertion (A) is false, but Reason (R) is true. ✓

   Answer: (D)

3. 3. CBSE 2026

   Direction : For question number 32, two statements are given – one labelled as Assertion (A) and other labelled as Reason (R). Select the correct answer to this question from the codes (A), (B), (C) & (D) as given below : Assertion (A) : With the help of compass, magnetic field lines can be traced outside the bar magnet. Reason (R) : The north pole of a compass needle always points towards the south pole of the magnet when brought close to it.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). ✓
   • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false.
   • (D) Assertion (A) is false, but Reason (R) is true.

   Answer: (A)

4. 4. CBSE 2026

   For Question number 32, two statements are given — one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to this question from the codes (A), (B), (C) and (D) as given below. Assertion (A) : Direction of force exerted on a current-carrying conductor placed in a magnetic field remains same if the directions of both magnetic field and current flowing through the conductor are reversed. Reason (R) : The direction of force exerted on a current-carrying conductor placed in an external magnetic field can be determined by using magnetic compass.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false. ✓
   • (D) Assertion (A) is false, but Reason (R) is true.

   Answer: (C)

5. 5. CBSE 2026

   For Question number 32, two statements are given - one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to this question from the codes (A), (B), (C) and (D) as given below. Assertion (A) : Direction of force exerted on a current-carrying conductor placed in a magnetic field remains same if the directions of both magnetic field and current flowing through the conductor are reversed. Reason (R) : The direction of force exerted on a current-carrying conductor placed in an external magnetic field can be determined by using magnetic compass.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false. ✓
   • (D) Assertion (A) is false, but Reason (R) is true.

   Answer: (C)

6. 6. CBSE 2026

   32. Assertion (A) : The needle of a magnetic compass kept in strong external magnetic field, always aligns itself in north-south direction on the earth. Reason (R) : Behaviour of the needle of a compass is same as that of a freely suspended bar magnet.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
   • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false.
   • (D) Assertion (A) is false, but Reason (R) is true. ✓

   Answer: (D)

7. 7. CBSE 2025

   Assertion (A) : In the common domestic circuits the earth wire is connected to a metallic plate buried deep inside the earth. Reason (R) : Earth wire ensures that any leakage of current to the metallic body of the appliance keeps its potential to that of the earth, so the user may not get a severe electric shock.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). ✓
   • (B) Both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of the Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false.
   • (D) Assertion (A) is false, but Reason (R) is true.

   Answer: (A)

8. 8. CBSE 2025

   Assertion (A) : No two magnetic field lines are found to cross each other. Reason (R) : The compass needle cannot point towards two directions at the point of intersection of two magnetic field lines.

   • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A). ✓
   • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
   • (C) Assertion (A) is true, but Reason (R) is false.
   • (D) Assertion (A) is false, but Reason (R) is true.

   Answer: (A)

9. 9. CBSE 2025

   Which one of the following statements is not true about a bar magnet ?

   • (A) It sets itself in north-south direction when suspended freely.
   • (B) It has attractive power for iron filings.
   • (C) It produces magnetic field lines.
   • (D) The direction of magnetic field lines inside a bar magnet is from its north pole to its south pole. ✓

   Answer: (D)

10. 10. CBSE 2025

    The strength of magnetic field produced inside a long straight current carrying solenoid does not depend upon :

    • (A) number of turns in the solenoid
    • (B) direction of current flowing through the solenoid
    • (C) material of the core filled inside the solenoid
    • (D) radius of the coil of the solenoid ✓

    Answer: (D)

Questions parents and students ask

How many marks does "Magnetic Effects of Electric Current" carry in CBSE Class 10 Science?

In the CBSE papers of 2023–2026, this chapter carried about 5 marks and about 2 questions a year; by marks it ranks 10 in Science.

Which are the most important (VVI) questions of "Magnetic Effects of Electric Current"?

The 20 questions above are from the board’s real papers, each with the years it was asked; the most-asked come first with their full model answers. All 35 written questions of this chapter, with answers, are in the AskMedha app.

Do the answers follow the board’s marking scheme?

Yes. CBSE publishes its marking schemes; every model answer here is written point by point to the marks the board’s own scheme gives, and checked by a second, independent model.