List of top Physics Questions

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?
If the ratio of the maximum and minimum amplitudes of an amplitude modulated wave is 7:3, then the modulation index is
For transmitting a signal of frequency 1000 kHz, the minimum length of the antenna is
As shown in the figure, if the values of the electric potential at three points A, B and C in a uniform electric field (\( \vec{E} \)) are \(V_A\), \(V_B\), and \(V_C\) respectively, then
electric potential at three points A, B and C
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
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)
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
To increase the RMS speed of gas molecules by 25%, the percentage increase in absolute temperature of the gas is to be
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 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
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
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
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:
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
The mean translational kinetic energy of a gas molecule at a temperature of 47 $^\circ$C is: (Boltzmann constant = 1.38 $\times$ 10$^{-23}$ J K$^{-1}$)
The circuit consisting of NAND gates that is equivalent to an AND gate is:
A mercury drop of radius \( 1 \) cm is divided into \( 10^6 \) droplets of equal size. If the surface tension of mercury is \( 35 \times 10^{-3} \) N/m, then the change in surface energy in the process is:
A particle is executing simple harmonic motion with amplitude \( A \). The ratio of the kinetic energies of the particle when it is at displacements of \( \frac{A}{4} \) and \( \frac{A}{2} \) from the mean position is:
A light ray incidents on an equilateral prism made of material of refractive index $\sqrt{3}$. Inside the prism, if the light ray moves parallel to the base of the prism, then the angle of incidence of the light ray is:
The magnitudes of two vectors \(\vec{A}\) and \(\vec{B}\) are \(A\) and \(B\) respectively, the magnitude of their resultant vector \(\vec{R}\) is \(R\). If \(\theta\) is the angle between the vectors \(\vec{A}\) and \(\vec{B}\), the angle made by the vector \(\vec{R}\) with the vector \(\vec{A}\) is \(\alpha\), then
Images of same size are formed by a convex lens when an object is placed either at 20 cm or 10 cm distance from the lens. The focal length of the lens is
A particle crossing the origin at time \(t = 0\), moves in the xy-plane with a constant acceleration ‘a’ in y-direction. If the equation of motion of the particle is \(y = bx^2\) (where \(b\) is a constant), then its velocity component in the x-direction is
The ratio of kinetic energy and total energy of a particle in simple harmonic motion, at a point where the displacement is 30% of its amplitude is:
If a 10 W bulb emits electromagnetic waves uniformly in all directions, then the intensity of light at a distance 0.5 m from the source is nearly