List of top Physics Questions

An engine pumps up $100 \,kg$ of water through a height of $10\, m$ in $5 s$. Given that the efficiency of engine is $60 \%$. If $g=10\, ms ^{-2}$, the power of the engine is

Two radioactive materials $X_1$, and $X_2$ have decay constants 5$\lambda$ and $\lambda$ respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of X$_1$ to that X$_2$ will be 1/e after a time

A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of $3 \times 10^6 \, ms^{-1}. $ The velocity of the particle is (mass of electron=$9.1 \times 10^{-31} \, kg) $

Two simple harmonic motions of angular frequency 100 and 1000 rad $s^1$ have the same displacement amplitude. The ratio of their maximum acceleration is

A steel ball of mass m falls in a viscous medium with a terminal velocity V. Another steel ball of mass 64m will fall through the same liquid with terminal velocity

In L-C-R series circuit the resonance condition in terms of capacitive reactance ($X_C$) and inductive reactance ($ X_L)$ is

A sphere of radius $R$ is gently dropped into liquid of viscosity $ \eta $ in a vertical uniform tube. It attains a terminal velocity $v$. Another sphere of radius $2\,R$ when dropped into the same liquid, will attain its terminal velocity

For a gas molecule with $6$ degrees of freedom the law of equipartition of energy gives the following relation between the molecular specific heat $(C_{V})$ and gas constant $(R)$

On bombardment of $U^{235}$ by slow neutrons, $200\, MeV$ energy is released. If the power output of atomic reactor is $1.6\, M\, W$, then the rate of fission will be

The area under the displacement-force curve gives

The height of the dam, in a hydroelectric power station is $ 10 \,m $ . In order to generate $ 1 \,MW $ of electric power, the mass of water (in kg) that must fall per second on the blades of the turbines is

The resonance frequency of the tank circuit of an oscillator when $ L=\frac{10}{{{\pi }^{2}}}mH $ and $ C=0.04\text{ }\mu F $ are connected in parallel is

A solid cylinder is rolling down on an inclined plane of angle $ \theta , $ The coefficient of static friction between the plane and cylinder is $ \mu _{s}$ . Then condition for the cylinder not to slip is

The average kinetic energy of a gas molecule is

The magnetic susceptibility of paramagnetic materials is

To convert a moving coil galvanometer $(MCG)$ into a voltmeter

The net magnetic flux through any closed surface, kept in a magnetic field is

Consider a thin spherical shell of radius $R$ consisting of uniform surface charge density $\sigma$ The electric field at a point of distance $x$ from its centre and outside the shell is

According to Lenz's law of electromagnetic induction

The energy released in the fission of $ 1 \,kg $ of $ _{92}{{U}^{235}} $ is (energy per fission = 200 MeV)

The work done in bringing at a unit positive charge from infinity distance to a point at distance $x$ from a positive charge $Q$ is $W$. Then the potential $ \phi $ at that point is

The latent heat of fusion of ice at $0^{\circ} C$ is $80\, cal / g$. Entropy change $(\Delta S)$ accompanying the melting of $1\, g$ of ice at $0^{\circ} C$ would be (units: $cal / g / K$ )

The frequency of the fundamental note in a wire stretched under tension $T$ is $f$. If the tension is increased to $25 \,T$, then the frequency of the fundamental note will be

When a $p-n$ junction diode is connected in forward bias its barrier potential