Question

A thin conducting rod MN of mass 20 gm, length 25 cm, and resistance 10Ω is held on frictionless long perfectly conducting vertical rails as in the figure. There is the uniform magnetic field B0=4T directed perpendicular to the plane of the rod-rail arrangement. the rod is released from rest at time t=0 and it moves down along the rails assuming air drag is negligible. Match each quantity in L-I with an appropriate value from L-II and choose the correct options(g=10ms$^{-2}$ and e$^{-1}$=0.4)

| List-I
| | List-II
---|---|---|---
(P)| At t=0.2s, the magnitude of induced emf in volt| (1)| 0.08
(Q)| At t=0.2s, the magnitude of magnetic force in N| (2)| 0.14
(R)| At t=0.2s, the power dissipated at heat in watt| (3)| 1.20
(S)| The magnitude terminal velocity of the rod in ms$^{-1}$| (4)| 0.12
| | (5)| 2.00

• A.

  P	Q	R	S
  4	3	2	1

• B.

  P	Q	R	S
  2	1	3	4

• C.

  P	Q	R	S
  3	4	2	5

• D.

  P	Q	R	S
  4	3	1	2

Answer 1

Answer: (C)

P	Q	R	S
3	4	2	5

Answer 2

magnetic force = i ℓ ℓ B = 0.12 N And power dissipated = 0.144 W Also, Terminal velocity = 2 m/s

The correct answer is (C): (P)3 (Q)4 (R)2 (S)5