List of top Physics Questions

A source of sound $S$ emitting waves of frequency $100\, Hz$ and an observor $O$ are located at some distance from each other. The source is moving with a speed of $19.4\, m s^{-1}$ at an angle of $60^{\circ}$ with the source observer line as shown in the figure. The observor is at rest. The apparent frequency observed by the observer is (velocity of sound in air $330\, ms ^{-1}$ )
For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index :
A deuteron of kinetic energy $50 \,keV$ is describing a circular orbit of radius $0.5$ metre in a plane perpendicular to the magnetic field $B$. The kinetic energy of the proton that describes a circular orbit of radius $0.5$ metre in the same plane with the same $B$ is
Find the number of photon emitted per second by a $25$ watt source of monochromatic light of wavelength $ 6600\, ??. What is the photoelectric current assuming $3\%$ efficiency for photoelectric effect ?
Kepler's third law states that square of period of revolution $(T)$ of a planet around the sun, is proportional to third power of average distance $r$ between sun and planet i.e. $T^{2}=K r^{3}$ here $K$ is constant. If the masses of sun and planet are $M$ and $m$ respectively then as per Newton's law of gravitation force of attraction between them is $F=\frac{G M m}{r^{2}}$ here $G$ is gravitational constant. The relation between $G$ and $K$ is described as
The approximate depth of an ocean is $2700\, m$. The compressibility of water is $45.4 \times 10^{-11} Pa ^{-1}$ and density of water is $10^{3} kg / m 3 .$ What fractional compression of water will be obtained at the bottom of the ocean?
Two spheres of different materials one with double the radius and one-fourth wall thickness of the other are filled with ice. If the time taken for complete melting of ice in the larger sphere is $25$ minute and for smaller one is $16$ minute, the ratio of thermal conductivities of the materials of larger spheres to that of smaller sphere is
The magnetic moment of atomic neon (in units of Bohr's magnetron) is
A ray of unpolarised light is incident on a glass plate at the polarising angle of $57^\circ$.
A light meter measures the intensity \( I \) of the light falling on it. Theory suggests that this varies as the inverse square of the distance \( d \). Which graph of the results supports this theory?
light meter measures the intensity I of the light
It takes 16 min to boil some water in an electric kettle. Due to some defect, it becomes necessary to remove 10% turns of heating coil of the kettle. After repairs, how much time will it take to boil the same mass of water?
The period of oscillation of a simple pendulum of length \( l \) suspended from the roof of a vehicle which moves down without friction on an inclined plane of inclination \( \theta \), is given by
When you flip a switch to turn on a light, the delay before the light turns on is determined by
If a guitar string is 0.5 m long, what is the wavelength of its third harmonic?
Although waves in the open ocean propagate in all directions, waves washing into any shore usually move nearly perpendicular to the shore. Which of the following best explains the reason for this phenomenon?
When a satellite is on the surface of a planet, it experiences a gravitational force $W$. What is the gravitational force when the satellite is at height $R/50$, where $R$ is the radius of the planet?
Consider a rotating spherical planet. The velocity of a point on its equator is $v$. The effect of rotation of the planet is to make $g$ at the equator $1/2$ of $g$ at the pole. What is the escape velocity for a polar particle on the planet expressed as a multiple of $v$?
A train accelerates from rest at a constant rate $\alpha$ for distance $X_1$ and time $t_1$. After that it retards to rest at constant rate $\beta$ for distance $X_2$ and time $t_2$. Then, it is found that
Different objects at different distances are seen by the eye. The parameter that remains constant is
The resistors in the circuits below each represent a light bulb. If all three circuits use the same size battery, which circuit will produce the most light?
The resistors in the circuits
A child swings a ball on a string in a circular motion. The ball moves in a plane vertical to the ground. If the sun is directly overhead how does the shadow move?
As given in the figure a series circuit connected across a 200 V, 60 Hz line consists of a capacitor of capacitive reactance 30 \( \Omega \), a non-inductive resistor 44 \( \Omega \), a coil of inductive reactance 90 \( \Omega \), and another resistance of 36 \( \Omega \). The power dissipated in the circuit is
series circuit connected across a 200 V,
The maximum and minimum distances of a comet from the Sun are $8 \times 10^{12} \, \text{m}$ and $1.6 \times 10^{12} \, \text{m}$. If its velocity when nearest to the Sun is $60 \, \text{m/s}$, what will be its velocity in m/s when it is farthest?
Four forces, 5 N North, 6 N 20° S of E, 9 N 20°N of W and 10 N South, act on an object. The equilibrium force equals
A gas undergoes a process in which its pressure p and volume V are related as \( V p^n = \text{constant} \). The bulk modulus of the gas in this pressure is