Title 06. ELECTROMAGNETIC INDUCTION.pdf ✅

06. ELECTROMAGNETIC INDUCTION NEET PREPARATION (MEDIUM PHYSICS PAPER) Date: March 12, 2025 Dura on: 1:00:00 Total Marks: 180 INSTRUCTIONS INSTRUCTIONS PHYSICS 1. A conducting loop being pulled out of magnetic field with a speed . Which of the following plots may represent the power delivered by the pulling agent as a function of the speed ? (1) (2) (3) (4) 2. The current in a circuit builds up to of its steady state value in . The time constant of this circuit is (1) (2) (3) (4) 3. Statement A : An emf can be induced by moving a conductor into a magnetic field. Statement B : An emf can be induced by changing the mag‐ netic field. (1) Statement A is correct but Statement B is incorrect. (2) Statement A is in- correct but Statement B is correct. (3) Both statements are correct. (4) Both Statements are incorrect. 4. A jet plane having a wing - span of is trav‐ eling horizontally towards east with a speed of . If the Earth's magnetic field at the location is and the angle of dip is , then the potential difference between the ends of the wing is (1) (2) (3) (4) 5. Magnetic flux (in weber) in a closed circuit of resistance varies with time as . The magnitude of induced current at is (1) (2) (3) (4) 6. A circuit contains two inductors of selfinduc‐ tance and in series. If is the mutual in‐ ductance then the effective inductance of the cir‐ cuit shown will be (1) (2) (3) (4) 7. In the figure, a conducting ring of certain resis‐ tance is falling towards a current carrying straight long conductor. The ring and conductor are in the same plane. Then the (1) induced electric current is zero (2) induced electric current is anticlockwise v v a b c d LR th 3 4 4 s s 4 In 2 s 3 In 3 s 2 In 2 s 1 In 2 25 m 3600 km/hour 4 × 10 −4 T 30 ∘ 4 V 5 V 2 V 2.5 V φ 10 Ω t(sec) φ = 6t 2 − 5t + 1 t = 0.25 s 0.2 A 0.6 A 1.2 A 0.8 A L1 L2 M L1 + L2 L1 + L2 − 2M L1 + L2 + M L1 + L2 + 2M


flows in such direction that it opposes the change or the cause the produced it. (1) Both Assertion and Reason are cor- rect and Reason is the correct explana- tion of the Assertion. (2) Both Assertion and Reason are cor- rect but Reason is not the correct explana- tion of the Assertion. (3) Assertion is cor- rect but Reason is incorrect. (4) Assertion is incor- rect but reason is correct. 32. Assertion : Only a change in magnetic flux will maintain an induced current in the coil Reason : The presence of large magnetic flux (1) Both Assertion and Reason are cor- rect and Reason is the correct explana- tion of the Assertion. (2) Both Assertion and Reason are cor- rect but Reason is not the correct explana- tion of the Assertion. (3) Assertion is cor- rect but Reason is incorrect. (4) Assertion is incor- rect but reason is correct. 33. A conducting circular loop is placed in a uni‐ form magnetic field of induction tesla with its plane normal to the field. Now, radius of the loop starts shrinking at the rate . Then the in‐ duced e.m.f at the instant when the radius is: (1) (2) (3) (4) 34. Statement A : Mutual inductance of a pair of coils depend on their separation as well as their relative orienta‐ tion. Statement B : Mutual inductance depends upon the length of the coils. (1) Statement A is correct but Statement B is incorrect. (2) Statement A is in- correct but Statement B is correct. (3) Both statements are correct. (4) Both Statements are incorrect. 35. Assertion : A spark occurs between the poles of a switch when the switch is opened. Reason : Current flowing in the conductor produces mag‐ netic field. (1) Both Assertion and Reason are cor- rect and Reason is the correct explana- tion of the Assertion. (2) Both Assertion and Reason are cor- rect but Reason is not the correct explana- tion of the Assertion. (3) Assertion is cor- rect but Reason is incorrect. (4) Assertion is incor- rect but reason is correct. 36. Assertion : An electric motor will have maximum efficiency when back emf becomes equal to half of applied Reason : Efficiency of electric motor does not depend on magnitude of back (1) Both Assertion and Reason are cor- rect and Reason is the correct explana- tion of the Assertion. (2) Both Assertion and Reason are cor- rect but Reason is not the correct explana- tion of the Assertion. (3) Assertion is cor- rect but Reason is incorrect. (4) Assertion is incor- rect but reason is correct. 37. A rectangular loop of length and width is placed at to magnetic field of The loop is removed from the field in The average induced in the loop during this time interval is : (1) (2) (3) (4) 38. In a coil, the current changes from to in and induces an emf of The self in‐ ductance of the coil is (1) (2) (3) (4) 39. An inductor of 2 henry and a resistance of 10 ohms are connected in series with a battery of 5 volts. The initial rate of change of current is: (1) (2) (3) (4) 40. The back induced in a coil, when current changes from 1 ampere to zero in one milli-sec‐ ond, is , the self inductance of the coil is (1) 1 henry (2) 4 henry (3) henry (4) henry 41. Two solenoids of equal number of turns have their lengths and the radii in the same ratio 1:2. The ratio of their self-inductances will be: B (dr/dt) r 2πrB ( ) dr dt πrB ( ) dr dt ( ) πr 2B 2 dr dt πr 2B ( ) dr dt emf. emf. 2.5 m 2 m 60 ∘ 4 T. 10 s. emf −2 +V √3 V −1 V −2A 2A 0.2s 0.1 V . 5 mH 4 mH 1 mH 2.5 mH 0.5 amp/ sec 2.0 amp/ sec 2.5 amp/ sec 0.25 amp/ sec emf 4 volts 10 −3 4 × 10 −3