List of top Physics Questions

An electric fan has blades of length 30 cm as measured from the axis of rotation. If the fan is rotating at 1200 rpm, the acceleration of a point on the tip of the blade is about

Two short magnets have equal pole strengths but one is twice as long as the other. The shorter magnet is placed 20 cm in tan A position from the compass needle. The longer magnet must be placed on the other side of the magnetometer for no deflection at a distance equal to

Two sound waves with wavelengths 5.0 m and 5.5. m respectively, each propagate in a gas with velocity 330 m/s. We expect the following number of beats per second :-

A transverse wave propagating along x-axis is represented by $y(x, t)=8.0 \sin(0.5\pi x-4\pi t-\pi/4)$ where x is in metres and t is in seconds. The speed of the wave is :-

A rectangular block of mass m and area of cross-section A floats in a liquid of density \(\rho\) . If it is given a small vertical displacement from equilibrium it undergoes oscillation with a time period T. Then :

An electric dipole of moment $\vec{p}$ is lying along a uniform electric field $\vec{E}$. The work done in rotating the dipole by 90$^{\circ}$ is :-

Two vibrating tuning forks produce waves given $y_1 = 4 \sin 500 \pi t$ and $y_2 = 2 \sin 506 \,\pi t.$ Number of beats produced per minute is

Kirchhoff's first and second laws of electrical circuits are consequences of

Two cells, having the same e.m.f. are connected in series through an external resistance R. Cells have internal resistances $r_1$ and $r_2\, (r_1 >\, r_2)$ respectively. When the circuit is closed, the potential difference across the first cell is zero. The value of R is :-

What is SI unit of electric field intensity?

The radioactivity of a sample is x at time $t_1$ and is y at time $t_2$. If the mean life of the specimen is $\tau$, the number of atoms that have disintegrated in the time interval $(t_2 - t_1)$ is

Emission of light stops as the incident light is cut-off in

You are given n resistors, each of resistance r. They are first combined to get minimum possible resistance, then they are connected to get the maximum possible resistance. The ratio between rrurnmum to maximum resistance is

A critical angle for a medium is $60^\circ.$ Then the refractive index of the medium will be

In a transistor amplifier, the two AC current gains $\alpha $ and $ \beta $ are defined as $\alpha=\frac{\partial I_C}{\partial I_E} $ and $ \beta =\frac{\partial I_C}{\partial I_B}$ the relation between $\alpha$ and $\beta$ is

If the magnetic flux is represented in weber, then the unit of magnetic induction will be

If the electric current in a lamp decreases by $5 \%,$ then the power output decreases by

The electric potential at the surface of an atomic nucleus (Z = 50) of radius $ 9 \times 10^{ - 15} \, m$ is

As electric dipole placed in a non-uniform electric field in such a way that angle between $p$ and $E$ is not $0^\circ$ or $ 180^\circ $, so it experiences

Two capacitors of capacitance $C_1$ and $C_2$, are connected in parallel. If a charge Q is given to the combination, the charge gets shared. The ratio of the charge on the capacitor $C_1$ to the charge on the capacitor $C_2$ is

A block of mass $ 2\,kg $ rests on a horizontal surface. If a horizontal force of $ 5\,N $ is applied on the block the frictional force on, it is $ (\mu _{k}=0.4,\,\mu _{s}=0.5) $

Electromagnetic waves can be deflected by

A bar magnet is held at right angles to a uniform magnetic field. The couple acting on the magnet is to be halved by rotating it from this position. The angle of rotation is

The velocity $v$ of a particle at time $t$ is given by $v=at+\frac{b}{t+c}$ , where $a$, $b$ and $c$ are constants. The dimensions of $a$, $b$ and $c$ are, respectively,

A rectangular vessel when full of water, takes $10$ minutes to be emptied through an orifice in its bottom. How much time will it take to be emptied when half filled with water ?