Question

Consider a rectangular loop or wire 6.0 cm by 8.0 cm in a uniform magnetic field of magnitude 1.3 T. The loop is rotated from a position of zero magnetic flux to a position of maximum flux in 21 ms. What is the average induced emf in the loop? (a) 0.1 V (b) 0.2 V (c) 0.3 V (d) 0.4 V (e) 0.5 V

Answer 1

option C

Step-by-step explanation:

given,

a rectangular loop of wire = 6 cm × 8 cm

magnetic field = 1.3 T

loop rotated from zero flux to maximum in 21 ms

to calculate average induced emf :

area of loop = 0.06 × 0.08 = 4.8 × 10⁻³ m²

maximum magnetic flux Φ₂ = B × A

= 1.3 × 4.8 × 10⁻³ = 6.24 × 10⁻³ Wb

Ф₁ = 0

time taken to change the position from Ф₁ to Φ₂ is 21 ms

average indused emf =
`\frac{\mathrm{d} \phi}{\mathrm{d} t}`

=
`(6.24 * 10^(-3)-0)/(21 * 10^(-3))`

= 0.297 = 0.3 V

hence, the correct answer is option C