# Electromagnetic Induction · Physics · COMEDK

Start Practice## MCQ (Single Correct Answer)

COMEDK 2024 Evening Shift

A conducting circular loop is placed in a uniform magnetic field $$\mathrm{B}=0.125 \mathrm{~T}$$ with its plane perpendicular to the loop. If the rad...

COMEDK 2024 Evening Shift

A transformer of $$100 \%$$ efficiency has 200 turns in the primary and 40000 turns in the secondary. It is connected to a $$220 \mathrm{~V}$$ main su...

COMEDK 2024 Evening Shift

The current in a coil changes steadily from $$3 \mathrm{~A}$$ to $$5 \mathrm{~A}$$ in $$0.2 \mathrm{~s}$$ when an emf of $$2 \mu \mathrm{V}$$ is induc...

COMEDK 2024 Evening Shift

The magnetic flux linked with a coil is given by the equation: $$\phi=8 t^2+t+10$$. The e.m.f. induced in the coil in the $$3^{\text {rd }}$$ second w...

COMEDK 2024 Morning Shift

Select the unit of the coefficient of mutual induction from the following.

COMEDK 2024 Morning Shift

Around the central part of an air cored solenoid of length $$20 \mathrm{~cm}$$ and area of cross section $$1.4 \times 10^{-3} \mathrm{~m}^2$$ and 3000...

COMEDK 2024 Morning Shift

A metallic rod of $$2 \mathrm{~m}$$ length is rotated with a frequency $$100 \mathrm{~Hz}$$ about an axis passing through the centre of the circular r...

COMEDK 2023 Morning Shift

The magnetic flux linked with a coil satisfies the relation $$\phi=\left(4 t^2+6 t+9\right) \mathrm{Wb}$$, where $$t$$ is time in second. The emf indu...

COMEDK 2023 Evening Shift

One volt induced emf is produced in the secondary coil when the current through the primary coil is changed from $$3 \mathrm{~A}$$ to $$1 \mathrm{~A}$...

COMEDK 2022

Television frequencies are of the order of 100 MHz, while radio frequencies are of the order of 1 MHz. Using these as typical frequencies, the ratio o...

COMEDK 2022

A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the co...

COMEDK 2020

A coil of wire of a certain radius has 100 turns
and a self inductance of 15 mH. The self
inductance of a second similar coil of 500 turns
will be...

COMEDK 2020

A coil of 100 turns carries a current of 5 mA and
creates a magnetic flux of 10$$^{-5}$$ Wb. The
inductance is

COMEDK 2020

In step-up transformer, relation between number of turns in primary (N$$_P$$) and number of turns in secondary (N$$_S$$) coils is