Question

A magnetic B field of strength 0.9 T is perpendicular to a loop with an area of 3 m2. If the area of the loop is reduced to zero in 0.5 s, then what is the magnitude of the induced emf voltage?

Answer 1

Answer:

The magnitude of induced emf is 5.4 V

Explanation:

Given:

Magnetic field $B = 0.9$ T

Area of loop $\Delta A = 3$ $m^{2}$

Time take to reduce loop to zero $\Delta t = 0.5$ sec

To find induced emf we use faraday's law,

Induced emf is given by,

  $\epsilon = -\frac{\Delta \phi}{\Delta t}$

Here minus sign shows lenz law, for finding magnitude of emf  we ignore it.

Where $\phi = B\Delta A$

Put the value of flux and find induced emf,

   $\epsilon = \frac{B\Delta A}{\Delta t}$

   $\epsilon = \frac{0.9 \times 3}{0.5}$

   $\epsilon = 5.4$ V

Therefore, the magnitude of induced emf is 5.4 V