List of top Physics Questions

In Young’s double-slit experiment with monochromatic light of wavelength 6000 Å, the fringe width is 3 mm. If the distance between the screen and slits is increased by 50\% and the distance between the slits is decreased by 10\%, then the fringe width is
A cockroach of mass \( m \) is moving with a velocity \( v \) in the anticlockwise direction on the rim of a disc of radius \( R \). The moment of inertia of the disc about the axis is \( I \) and it is rotating in a clockwise direction with an angular velocity \( \omega \). If the cockroach stops moving, the angular velocity of the disc will be:
A piston divides a closed gas cylinder into two parts. Initially, the piston is kept pressed such that one part has pressure P and volume 5V and the other part has pressure 8P and volume V. The piston is now left free. The new pressure if the process is isothermal:
A solid flywheel of mass 20 kg and radius 100 mm revolves at 600 revolutions per minute. If the coefficient of friction is 0.1 and to stop the flywheel in 3.14 s, the force to be applied against is approximately:
Path of projectile is given by the equation \( Y = Px - Qx^2 \), match the following accordingly (acceleration due to gravity = \( g \))
Path of projectile is given by the equation Y = Px−Qx2
Match the following (\( f \) is the number of degrees of freedom): \includegraphics[]{100.png}
Two spheres A & B of radii 4 cm & 6 cm are given charges of 80 µC & 40 µC respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is:
In which of the following thermodynamic processes, the total amount of heat supplied to the system is only used to rise the temperature?
The elastic energy stored per unit volume in terms of longitudinal strain \( e \) and Young’s modulus \( Y \) is:
Electric field intensity and electric potential at a point due to a point charge are 600 V/m and -3600 V respectively. The distance of the point from the charge and the magnitude of the charge are:
When the temperature of a gas is raised from 27°C to 90°C, the increase in the rms velocity of the gas molecules is:
A blue lamp emits light of mean wavelength 4500\({Å}\). The lamp is rated at 150 W and 8% efficiency. Then the number of photons are emitted by the lamp per second.
A body slides down an inclined plane of angle of inclination 30\(^\circ\) with a constant velocity of 10 ms\(^{-1}\). If the body is pushed up the same plane with a velocity of 20 ms\(^{-1}\), the distance moved by the body before coming to rest is (acceleration due to gravity = 10 ms\(^2\))
The molar specific heat capacity of a diatomic gas at constant pressure is \( C \). The molar specific heat capacity of a monatomic gas at constant volume is

In the given circuit the currents are \( I_1 = 5A \), \( I_4 = 10A \), and \( I_5 = 15A \). Analyzing the circuit using Kirchhoff’s laws, then \( I_2 \), \( I_3 \), and \( I_6 \) values are:

A parallel plate capacitor has two square plates of side 5 cm separated by 15 mm. A Pyrex glass slab of dielectric constant \(K = 4.5\) and thickness 10 mm is placed between the plates. The capacitance of the capacitor is:

In the given LCR series circuit the quality factor is


 

The speed of the electron in a hydrogen atom in the \( n = 3 \) level is:

A force of \( (4\hat{i} + 2\hat{j} + \hat{k}) \) N is acting on a particle of mass \( 2 \) kg displaces the particle from a position of \( (2\hat{i} + 2\hat{j} + \hat{k}) \) m to a position of \( (4\hat{i} + 3\hat{j} + 2\hat{k}) \) m. The work done by the force on the particle in joules is:
A 2 kg ball is thrown vertically upward and another 3 kg ball is projected with a certain angle (\( \theta \neq 90^\circ \)). Both will have the same time of flight. The ratio of their maximum heights is:
Two light waves of intensities \( I \) and \( 2I \) superimpose on each other. If the path difference between the light waves reaching a point is 12.5% of the wavelength of the light, then the resultant intensity at the point is (Both the light waves have the same wavelength)

An inductor and a resistor are connected in series to an AC source of voltage \( 144\sin(100\pi t + \frac{\pi}{2}) \) volts. If the current in the circuit is \( 6\sin(100\pi t + \frac{\pi}{2}) \) amperes, then the resistance of the resistor is:

In a spring-block system as shown in the figure, if the spring constant \( K = 9 \, {N/m} \), then the time period of oscillation is:
A metallic wire of resistance 30 \( \Omega \) is bent in the form of an equilateral triangle. The resistance between any two vertices of the triangle is:

A lens with refractive index \( \frac{3}{2} \) has a power of +5 diopters in air. If it is completely immersed in water, its power is (in diopters).
The refractive index of water is \( \frac{4}{3} \)