Question

The plane of a rectangular coil, 3.7 cm by 3.7 cm, is perpendicular to the direction of a uniform magnetic field B. If the coil has 61 turns and a total resistance of 8.4 Ω, at what rate must the magnitude of B change to induce a current of 0.04 A in the windings of the coil?

Answer 1

Answer:3.77 T/s

Explanation:

Given

Area of cross-section$=3.7\times 3.7 cm^2=13.69 cm^2$

N=no of turns=61

Resistance=$R=8 \Omega$

current (i)=0.04 A

emf induced$=i\times R=0.04\times 8=0.32 V$

emf induced $e=NA\frac{\mathrm{d} B}{\mathrm{d} t}$

$0.32=62\times 13.69\times 10^{-4}\times \frac{\mathrm{d} B}{\mathrm{d} t}$

$\frac{\mathrm{d} B}{\mathrm{d} t}=\frac{0.32\times 10^4}{848.78}=3.77 T/s$