List of top Physics Questions

If the error in the measurement of the surface area of a sphere is 1.2%, then the error in the determination of the volume of the sphere is
A solid of mass 1 kg has \(6 \times 10^{24}\) atoms. If one electron is removed from every one atom of 0.005% of the atoms, then the charge gained by the solid is
If the ratio of the maximum and minimum amplitudes of an amplitude modulated wave is 7:3, then the modulation index is
If a ball projected vertically upwards with certain initial velocity from the ground crosses a point at a height of 25 m twice in a time interval of 4 s, then the initial velocity of the ball is
(Acceleration due to gravity $= 10~\text{m/s}^2$)
The de Broglie wavelength associated with an electron accelerated through a potential difference of \( \frac{200}{3} \ \text{V} \) is nearly
A vector perpendicular to the vector $\left(4\hat{i} - 3\hat{j}\right)$ is
The energy stored in a coil of inductance 50 mH carrying a current of 2 A is:
Two capacitors of capacitances \( 4 \, \mu\text{F} \) and \( 6 \, \mu\text{F} \) are connected in series across a potential difference of \( 300 \, \text{V} \). What is the potential difference across the \( 4 \, \mu\text{F} \) capacitor?
A 10 $\mu$C charge is placed at the vertex A of an equilateral triangle ABC of side 2 m. The work done in taking another charge $(3 + \sqrt{3})$ $\mu$C from the mid point of BC to the mid point of the side AC is:
As shown in the figure, the work done to move the charge 'Q' from point C to point D along the semi-circle CRD is
work done to move the charge ’Q’ from point C to point D
A bomb of mass 12 kg at rest explodes into two pieces of masses 4 kg and 8 kg. If the velocity of 8 kg mass is \( 6\,{ms}^{-1} \), then the kinetic energy of 4 kg mass is
For transmitting a signal of frequency 1000 kHz, the minimum length of the antenna is
If the amplitude of electric field vector and frequency of an electromagnetic wave travelling along $z$-direction in vacuum are 180 N C$^{-1}$ and 60 GHz respectively, then the equation of the magnitude of the electric field of the plane electromagnetic wave is
If a particle is moving along a circle of radius \( r \) with constant speed \( v \), then the magnitude of the change in velocity when the particle moves from \( P \) to \( Q \), where \( PQ \) makes an angle \( \theta \) at the center of the circle is:
If 2 moles of an ideal monoatomic gas at a temperature of 27 °C is mixed with 4 moles of another ideal monoatomic gas at a temperature of 327 °C, then the temperature of the mixture of the two gases is
The efficiency of a Carnot's heat engine is \( \frac{1}{3} \). If the temperature of the source is decreased by \(50^\circ \text{C}\) and the temperature of the sink is increased by \(25^\circ \text{C}\), the efficiency of the engine becomes \( \frac{3}{16} \). The initial temperature of the sink is
To increase the RMS speed of gas molecules by 25%, the percentage increase in absolute temperature of the gas is to be
If the far point of a short sighted person is 400 cm, then the power of the lens required to enable him to see very distant objects clearly is
A balloon with mass 'm' is descending vertically with an acceleration 'a' (where a \(<\) g). The mass to be removed from the balloon, so that it starts moving vertically up with an acceleration 'a' is

The ratio of the currents i$_1$, i$_2$ and i$_3$ in the circuit is:

The work done to increase the volume of 2 moles of an ideal gas from \( V \) to \( 2V \) at a constant temperature \( T \) is \( W \). The work to be done to increase the volume of 2 moles of the same gas from \( 2V \) to \( 4V \) at the same constant temperature \( T \) is:
If current of 80 A is passing through a straight conductor of length 10 m, then the total momentum of electrons in the conductor is (mass of electron \( = 9.1 \times 10^{-31} \) kg and charge of electron \( = 1.6 \times 10^{-19} \) C)
The speed of a stationary wave represented by the equation $y = 0.75 \sin\left(\dfrac{7\pi}{4}x\right)\cos(350\pi t)$ is
A coil of inductive reactance $\frac{1}{\sqrt{3}} \Omega$ and a resistance 1 $\Omega$ are connected in series to a 200 V, 50 Hz ac source. The time lag between voltage and current is
When both the source of sound and observer approach each other with a speed equal to 10% of the speed of sound, then the percentage change in frequency heard by the observer is nearly