Figure shows a conducting rod of negligible resistance that can slide on smooth U-shaped rail made of wire of resistance 1Ω/ m . Position of the conducting rod at t = 0 is shown. A time dependent magn

Question

Figure shows a conducting rod of negligible resistance that can slide on smooth U-shaped rail made of wire of resistance $1Ω/ m$ . Position of the conducting rod at $t = 0$ is shown. A time dependent magnetic field $B = 2 t$ Tesla is switched on at $t = 0$ . After the magnetic field is switched on, the conducting rod is moved to the left perpendicular to the rails at constant speed 5 cm/s by some external agent.

TestHub · Accepted Answer

ε = d t d ϕ ​ = B d t d A ​ + A d t d B ​ (A) At t = 0: ε = A d t d B ​ = ( 0.4 × 0.2 ) × 2 = 0.16 V ; R = ( 2 × 0.4 + 0.2 ) × 1 = 1 Ω ⇒ I = 0.16 A , clockwise (flux outward increasing) ⇒ CORRECT (B) At t = 2 s: rod moved 10 cm left, ℓ = 30 cm , A = 0.06 m 2 : ε = 4 × ( 0.2 × 0.05 ) + 0.06 × 2 = − 0.04 + 0.12... ∣ ε ∣ = 0.08 V ⇒ CORRECT (C) R = ( 2 × 0.3 + 0.2 ) = 0.8 Ω ; I = 0.8 0.08 ​ = 0.1 A ; F = B I ℓ w i d t h ​ = 4 × 0.1 × 0.2 = 0.08 N ⇒ CORRECT, (D) incorrect

Physics - EMI/AC Question with Solution | TestHub

Options:(select one or more)

Doubts & Discussion