Physics MCQs for NEET — Practice Questions with Answers

A 800 turn coil of effective area 0.05 $m^2$ is kept perpendicular to a magnetic field $5\times {10}^{-5} T$. When the plane of the coil is rotated by 90$°$ around any of its coplanar axis in 0.1 s, the emf induced in the coil will be:

The sun delivers ${10}^3 w/m^2$ of electromagnetic flux to the earth's surface.  The total power that is incident on a roof of dimensions 8 m$\times$20 m will be

Displacement current is :

A circular ring of radius r is placed in a homogeneous magnetic field perpendicular to the plane of the ring. The field B changes with time according to the equation B = Kt, where K is a constant and t is the time. The electric field in the ring is

A cycle wheel of radius 0.5 m is rotated with a constant angular velocity of 10 rad/s in a region of a magnetic field of 0.1 T which is perpendicular to the plane of the wheel. The EMF generated between its centre and the rim is:

If the current in an AC circuit is given as $\mathrm{i}=\left(5\mathrm{A}\right)\sin \left(\mathrm{\omega t}-\frac{\mathrm{\pi }}{3}\right)$ when an emf $\mathrm{e}=\left(200\mathrm{V}\right)\mathrm{sin\omega t}$ is applied across the circuit. The circuit having component only

A step-down transformer is employed to reduce the main supply of AC from 220V to 11V. If the primary coil draws a current of 5A and the secondary supplies a current of 90A, then the efficiency of the transformer is  -

At resonance, the value of the power factor of the circuit is -

In a LCR circuit having L = 8.0 henry, C = 0.5 $\mathrm{\mu F}$ and R = 100 $\mathrm{\Omega }$ in series, the resonance frequency (in Hz) is 

In a LCR series network, ${\mathrm{V}}_{\mathrm{L}}=40 \mathrm{V}, {\mathrm{V}}_{\mathrm{C}}=20 \mathrm{V} \mathrm{and} {\mathrm{V}}_{\mathrm{R}}=15 \mathrm{V}$. The supply voltage is