List of top Physics Questions

An electron moving along a straight line with a velocity of $6.4 \times 10^7 ms^{-1}$ is subjected to a magnetic field of 3 mT. If the magnetic field is applied perpendicular to the direction of the initial path of the electron, then the radius of the circular path in which the electron moves under the influence of the magnetic field is (Mass of electron $= 9 \times 10^{-31}$ kg and charge of the electron $= 1.6 \times 10^{-19}$ C)
When an unknown resistance is connected in the left gap and a resistance of 15 $\Omega$ is connected in the right gap of a meter bridge, the balancing point is found to be at 40 cm from the left end of the bridge wire. The emf of the battery of negligible internal resistance used in the circuit is 2 V. If the current drawn from the battery is 280 mA, the resistance of the bridge wire per unit length is
The angle between the axes of the polarizer and the analyzer is $60^{\circ}$. The ratio of the intensity of unpolarized light incident on the polarizer and the intensity of the polarized light emerging from the analyzer is
A convex lens made of glass of refractive index 1.5 is immersed in a liquid. If the focal length of the lens when immersed in the liquid is twice its focal length when it is in air, then the refractive index of the liquid is
Three resistors $R_1, R_2$ and $R_3$ when connected in parallel to a battery of negligible internal resistance, the currents through the three resistors are 2A, 3A and 6A respectively. If the resistors are connected in series to the same battery, the current in the circuit is
Two points A and B are located at distances 4 cm and 5 cm respectively from a point charge $+20\mu C$. The work done in taking a charge of $+2\mu C$ from point A to point B is
A ray of light is travelling from a medium of refractive index 1.414 to air. If the angle of incidence is $48^{\circ}$, then the angle of deviation of the light ray is
Two point charges $+2\mu C$ and $+8\mu C$ are placed at a distance of 15 cm apart in air. At a point on the line joining these two charges where the net electric field becomes zero, a third charge of $+5\mu C$ is placed. The net electrostatic force acting on $+5\mu C$ charge is
When a long hollow steel pipe is struck with a hammer at one end, two sounds are heard at the other end. If the time interval between the two sounds heard is 0.53 s, then the length of the pipe is
(Speed of sound in steel is 5100 $ms^{-1}$ and speed of sound in air is 330 $ms^{-1}$)
If the coefficient of volume expansion of honey is $150 \times 10^{-5} K^{-1}$, then the percentage change in its density for $10^{\circ}C$ rise in its temperature is
The heat supplied to an ideal diatomic gas so that it expands from a volume of $18 \times 10^{-3} m^3$ to $37 \times 10^{-3} m^3$ at a constant pressure of 2 atmospheres is (Atmospheric pressure = $10^5$ Pa)
A radar sends sound waves of frequency 'f' towards an aeroplane moving away from it. If the difference in the frequencies of waves sent and received by the radar is 10% of 'f', then the speed of the aeroplane in $ms^{-1}$ is nearly (Speed of sound in air = 342 $ms^{-1}$)
The time period of a particle executing simple harmonic motion is $2\pi$ second. If the maximum acceleration of the particle is $10 ms^{-2}$, then the maximum velocity of the particle is
The pressure inside a mercury drop of diameter 2 mm is (Surface tension of mercury $= 0.5 Nm^{-1}$ and atmospheric pressure $= 10^5$ Pa)
A solid sphere of mass M and radius R is placed inside a spherical shell of mass M and radius 4R such that their surfaces touch each other. The gravitational force due to the spherical shell and solid sphere on a body of unit mass placed at the centre of the spherical shell is (G = Universal gravitational constant)
A metal beam of length 1 m, breadth 2.5 cm and thickness 5 mm supported at its ends is loaded at its center by a weight of 25 N. The metal beam sags at the middle by an amount of (Young's modulus of the metal $= 2\times10^{11} Nm^{-2}$)
A solid sphere of mass 2 kg and radius 50 cm is rotating about its diameter with an angular speed of $50 rad s^{-1}$. The angular momentum of the sphere is
Petrol (density $= 750 \, kg m^{-3}$) and diesel (density $= 850 \, kg m^{-3}$) enter into two identical venturimeters each with a velocity $10 ms^{-1}$ as shown in the figure. If $\Delta h_1$ is the difference in heights of petrol in the two vertical tubes of venturimeter A and if $\Delta h_2$ is the difference in heights of diesel in the two vertical tubes of the venturimeter B, then $\Delta h_1 : \Delta h_2 =$
Two vectors are given by $\vec{A} = \hat{i} - 2\hat{j} + 3\hat{k}$ and $\vec{B} = 2\hat{i} - 4\hat{j} + 3\hat{k}$. The unit vector along $\vec{A} + \vec{B}$ is
A body of mass 0.2 kg is falling freely from a height of 180 m from the ground. The ratio of the works done by the gravitational force in the first two seconds and in the next two seconds of motion of the body is
A body is allowed to fall freely under gravity from a height of 15 m from the ground. At a point in its path, if the kinetic energy of the body is 200% more than its potential energy, then the velocity of the body at that point is (Acceleration due to gravity = 10 $ms^{-2}$)
A body of mass 3 kg is kept on a rough horizontal surface. A horizontal force of 20 N acting on the body produces an acceleration of $4 ms^{-2}$ in the body. To double the acceleration of the body, the horizontal force applied is to be increased by
A series LCR circuit is connected to an alternating source of emf \( E \). The current amplitude at resonance frequency is \( I_0 \). If the value of resistance \( R \) becomes twice of its initial value, then amplitude of current at resonance will be:
Which one of the following is the correct dimensional formula for the capacitance in F? M, L, T, and C stand for unit of mass, length, time, and charge.
If the frequencies of the carrier wave and message signal are $1$ MHz and $28$ kHz respectively, then the frequencies of the side bands are