A band of 500 rectangular loops of wire of area 20cm by 20cm; encloses a region of magnetic field which charges from 1.0T to 0.4T within 5 seconds; calculate the induced e.m.f.

A. 5.60 v
B. 24.00 v
C. 0.24 v
D. 2.40 v

Correct Answer:

Option D = 2.40 v

Explanation

Number of tunes, n = 500
Area, A = 0.2m + 0.2m = 0.4m²
change of flux density A B
= 1.0 – 0.4 = 0.6T
Tune, t = 5 su
Induced emf, ξ = (AB AN)/AT
(0.6 x 0. 04 x 500)/5
= 2.4v