Question

A conducting circular loop made of a thill wire, has area 3.5 × 10^–3 m² and resistance 10$Ω$. It is placed perpendicular to a time dependent magnetic field B(t) = (0.4T)sin(50$\pi$t). The field is uniform in space. Then the net charge flowing through the loop during t = 0 s and t = 10 ms is close to:

(1) 14 mC 

(2) 21 mC 

(3) 6 mC 

(4) 7 mC

Answer 1

Ans: None

Sol: $Q={\Delta\phi\over R}={1\over10}A(B_f-B_i)$

$={1\over10}\times3.5\times10^{-3}(0.4\sin{\pi\over2}-0)$

$={1\over10}(3.5\times10^{-3})(0.4-0)$

$=1.4×10^{–4}=0.14\text{ }mC$