Following questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Q.1. Assertion(A): On changing the direction of flow of current through a straight conductor, the direction of a magnetic field around the conductor is reversed.
Reason (R) : The direction of magnetic field around a conductor can be given in accordance with left hand thumb rule.
Answer
(c)Q.2. Assertion(A): The magnitude of the magnetic field at a point on the axis of a current carrying solenoid is inversely proportional to the current flowing through the solenoid.
Reason (R) : The magnitude of the magnetic field at a point on the axis of a current carrying solenoid is directly proportional to the number of turns per unit length of a solenoid.
Answer
(d)Q.3. Assertion(A): A compass needle is placed near a current carrying wire. The deflection of the compass needle decreases when the magnitude of an electric current in the wire is increased.
Reason (R) : Strength of a magnetic field at a point near the conductor increases on increasing the current.
Answer
(d)Q.4. Assertion(A) : A compass needle is placed near a current carrying wire. The deflection of the compass needle decreases when the compass needle is displaced away from the wire.
Reason (R) : Strength of a magnetic field decreases as one moves away from a current carrying conductor.
Answer
(a)Q.5. Assertion(A) : The strength of the magnetic field produced at the centre of a current carrying circular coil increases on increasing the current flowing through the coil.
Reason (R) : Magnetic field strength is inversely proportional to the current flowing in the coil.
Answer
(c)Q.6. Assertion(A) : The strength of the magnetic field produced at the centre of a current carrying circular coil increases on increasing the radius of the circular coil.
Reason (R) : Magnetic field strength is inversely proportional to the radius of the circular coil.
Answer
(d)Q.7. Assertion(A) : The strength of the magnetic field produced at the centre of a current carrying circular coil increases on increasing the number of turns of the circular coil.
Reason (R) : Magnetic field strength is directly proportional to the number of turns of the circular coil.
Answer
(a)Q.8. Assertion(A) : On freely suspending a current-carrying solenoid, it comes to rest in N-S direction just like a bar magnet.
Reason (R) : One end of current carrying straight solenoid behaves as a North pole and the other end as a South pole.
Answer
(a)Q.9. Assertion(A) : Alternating Current is used in household supply.
Reason (R) : AC electric power can be transmitted over long distances without much loss of energy.
Answer
(a)Q.10. Assertion(A) : The strength of the magnetic field at the centre of a circular coil of a wire depends on the radius of the coil
Reason (R) : The strength of the magnetic field at the centre of a circular coil of a wire depends on the number of turns of the wire in the coil.
Answer
(b)Q.11. Assertion(A) : A current carrying wire deflects a magnetic needle placed near it.
Reason (R) : A magnetic field exists around a current carrying wire.
Answer
(a)Q.12. Assertion(A) : Strength of an electromagnet can be increased by increasing the number of turns per unit length in solenoid coil.
Reason (R) : Strength of an electromagnet can be increased by increasing the current flowing through the solenoid.