MHT CET 2025 20th April Morning Shift | Electromagnetic Induction Question 16 | Physics

The coefficient of mutual induction is 2 H and induced e.m.f. across secondary is 2 kV . Current in the primary is reduced from 6 A to 3 A . The time required for the change of current is

$4 \times 10^{-3} \mathrm{~s}$

$6 \times 10^{-3} \mathrm{~s}$

$2 \times 10^{-3} \mathrm{~s}$

$3 \times 10^{-3} \mathrm{~s}$

MHT CET 2025 20th April Morning Shift

MCQ (Single Correct Answer)

-0

Two planar concentric rings of metal wire having radii $\mathrm{r}_1$ and $\mathrm{r}_2\left(\mathrm{r}_1>\mathrm{r}_2\right)$ are placed in air. The current I is flowing through the coil of larger radius. The mutual inductance between the coils is given by ( $\mu_0=$ permeability of free space)

$\frac{\mu_0 \pi r_1^2}{2 r_2}$

$\frac{\mu_0 \pi r_1^2}{2 r_1}$

$\frac{\mu_0 \pi\left(r_1+r_2\right)^2}{2 r_1}$

$\frac{\mu_0 \pi\left(r_1-r_2\right)^2}{2 r_2}$

MHT CET 2025 19th April Evening Shift

MCQ (Single Correct Answer)

-0

Out of the following which law obeys the law of conservation of energy?

Kirchhoff's $1^{\text {st }}$ law in electricity.

Lenz's law in induction.

Ampere's circuital law.

Gauss's law in electrostatics.

MHT CET 2025 19th April Evening Shift

MCQ (Single Correct Answer)

-0

The magnetic flux through a coil is $4 \times 10^{-4} \mathrm{~Wb}$ at time $t=0$. It reduces to $30 \%$ of its original value in time $t$ second. If e.m.f. induced in the coil is 0.56 mV then the value of $t$ is

0.5 s

$\quad 0.4 \mathrm{~s}$

0.8 s

0.7 s

PREVIOUS NEXT

MHT CET Subjects