Question

A magnetic field is normal to the plane of a 0.15 m x 0.30 m rectangular coil of 120 turns. The magnetic field is increased uniformly from 0.10 T to 1.5 T. Find the time interval for the change if an emf induced in the coil is 1.2 V.Group of answer choices0.23 s2.6 s6.3 s9.6 s

Answer 1

Given:

The number of turns in the coil is N = 120 turns

The emf induced in the coil is

$\epsilon\text{ = 1.2 V}$

The change in the magnetic field is

$\begin{gathered} \Delta B=\text{ 1.5-0.1} \\ =1.4\text{ T} \end{gathered}$

The area of the coil is

$\begin{gathered} A\text{ = 0.15}\times0.3 \\ =0.045\text{ m}^2 \end{gathered}$

To find the time interval.

Explanation:

The time interval can be calculated by the formula

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

On substituting the values, the time interval will be

$\begin{gathered} \Delta t\text{ = }\frac{120\times0.045\times1.4}{1.2} \\ =6.3\text{ s} \end{gathered}$

Final Answer: The time interval is 6.3 s