Figure shows a conducting rod of negligible resistance that can slide on smooth U-shaped rail made of wire of resistance 1 Ω /m. position of the conducting rod at t = 0 is shown. A time t dependent magnetic field B = 2t tesla is switched on at t = 0
(i) The current in the loop at t = 0 due to induced emf is –
Text Solution
Verified by ExpertsCHECK THE SOLUTION.
Ans.
(i)
Sol. 
= 2T/s
E = – 
= – 800 × 10 –4 m 2 × 2 = – 0.16 V
i = 
= 0.16 A, clockwise
(ii)
Sol. At t = 2s, B = 4T, 
2T/s
A = 20 × 30 cm 2 = 600 × 10
–4 m 2 ; 
–(5 × 20) cm 2 /s
= – 100 × 10 –4 m 2 /s
= – [4 × (– 100 × 10 –4 ) + 600 × 10 –4 × 2]
= – [–0.04 + 0.120] = – 0.08 v
(iii)
Sol. At t = 2s, length of the wire
= (2 × 30 cm) + 20 cm = 0.8 m
Resistance of the wire = 0.8 Ω
Current through the rod 
A
Force on the wire = ilB = 
× (0.2) × 4 = 0.08 N
same force is applied on the rod in opposite direction to make net force zero.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems