List of top Physics Questions

The potential difference across the collector of a transistor, used in common emitter mode is $1.5\, V$, with the collector resistance of $3\, k\Omega$, the emitter current is $[\beta = 50]$
A horizontal disk is rotating with angular velocity $\omega $ about a vertical axis passing through its centre. A ball is placed at the centre of groove and pushed slightly. The velocity of the ball when it comes out of the groove-
A car is moving with speed $20 \, \, \text{m s}^{- 1}$ on a circular path of radius $100 \, \, \text{m}$ . Its speed is increasing at a rate of $3 \, \text{m s}^{- 2}$ . The magnitude of the acceleration of the car at that moment is
The normal reaction on a body placed in a lift moving up with constant acceleration $2 \, m \, s^{- 1}$ is $120 \, N$ . Mass of the body is (Take $g=10 \, m \, s^{- 2}$ )
A block of mass $M$ is resting on a smooth horizontal plane. One end of a uniform rope of mass $\frac{M}{4}$ is fixed to the block, which pulled it in the horizontal direction by applying a force $F$ at the other ends. The tension in the middle of the rope is
For the arrangement in the figure, the particle $M_{1}$ attached to one end of a string which moves on a horizontal table in a circle of radius $=\frac{l}{2}$ (where $l$ is the length of the string) with the constant angular speed $\omega $ . The other end of the string attached to mass $M_{2}$ which rests on a vertical rod. When the rod collapse, the acceleration of mass $M_{2}$ at that instant
Three blocks are connected, as shown in the figure. Calculate the minimum force required to move the blocks with constant velocity. The co-efficient of friction at all surfaces is $0.25$ . [Assume that rod does not exerts force in vertical direction]
$\,^{221}_{87}$Ra undergoes radiorctive decay with a half life of 4 days. The probability that a Ra nucleus will disintegrate in 8 days is
$175$ calorie of heat is required to raise the temperature of $5$ mole of an ideal gas at constant pressure from $30^\circ\,C$ to $35^\circ\,C$. The amount of heat required to raise temperature of same gas from $30^\circ\,C$ to $35^\circ\,C$ constant volume will be
A resistor, capacitor and an inductor are connected in series and are in resonance. What is the phase difference between the supplied voltage and current ?
Capacitance of a spherical conductor of radius $R$ is proportional to
What is the relationship between electric field intensity $E$, current density $J$ and specific resistance $\rho$ ?
When a pentavalent impurity is added in Ge crystal then, what type of semiconductor is obtained ?
A person suffering from myopia should use a
If two waves of same amplitude A each produce Maximum Marks 600 a resultant wave of amplitude equal to one of its wave, then the phase difference between them will be
At what temperature the root mean square velocity of a gas is twice of its root mean velocity at $27^{\circ} C $?
In a triode, $\mu, g_{m}$ and $r_{p}$ are related as
$120\, AC$ voltage is applied to $10$ ohm resistance. The peak voltage across the resistor is
The average kinetic energy of a molecule of a gas at absolute temperature T is propor tional to
The following four gases are at the same temperature. In which gas do the molecules have the maximum root mean square speed?
If k is the Boltzmann cottstant, the average kinetic energy of a gas molecule at absolute temperature T is
At a given temperature if $V_{rms}$ is the root mean square velocity of the molecules of a gas and $V_s$ be the velocity of sound in it, then these are related as $\left(\gamma = \frac{C_p}{C_v}\right)$
The heat required to raise the temperature of one mole of gas by 1$^\circ$C at constant volume is $k$ times that required to raise the temperature of one mole of triatomic gas at constant pressure. What is the value of $k$ ?
Statement 1. Boyle's law is independent of the selection of scale of temperature.$\,$ Statement 2. Boyle's law does not hold good for a gas at low temperature and high pressure.
The relation between volume V, pressure P and absolute temperature T of an ideal gas is $PV = x T$ where x is a constant The value of x depends upon