List of top Physics Questions

In Wheatstone bridge, 4 resistors \( P = 10 \, \Omega \), \( Q = 5 \, \Omega \), \( R = 4 \, \Omega \), \( S = 4 \, \Omega \) are connected in cyclic order. To ensure no current through galvanometer,
In photoelectric effect, initially when energy of electrons emitted is \( E_0 \), de-Broglie wavelength associated with them is \( \lambda_0 \). Now, energy is doubled then associated de-Broglie wavelength \( \lambda' \) is
In given circuit, \( C_1 = C_2 = C_3 = C \) initially. Now, a dielectric slab of dielectric constant \( K = \frac{3}{2} \) is inserted in \( C_2 \). The equivalent capacitance becomes
Average energy in one time period of a simple harmonic oscillator whose amplitude is A, angular velocity $\omega$ and mass m, is:
A pendulum with a period of 2 seconds at sea level has its length doubled. Its new period is now most nearly:
A proton and an electron are placed in a uniform electric field. Which of the following is correct?
A long string with a charge of a per unit length passes through an imaginary cube of edge L.
The maximum possible flux of electric field through the cube will be
A string of length $\ell$ is fixed at both ends. It is vibrating in its $3^{rd}$ overtone with maximum amplitude '$a$'. The amplitude at a distance $\ell /3$ from one end is.
The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance \(R_1\) will be
two ideal diodes
A resistor of resistance $R$, capacitor of capacitance $C$ and inductor of inductance $L$ are connected in parallel to $A C$ power source of voltage $\epsilon_{0} \sin \omega_{t}$. The maximum current through the resistance is half of the maximum current through the power source. Then value of $R$ is
Two identical charged spheres suspended from a common point by two massless strings of lengths $l$, are initially at a distance $d(d < < l)$ apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity $v$. Then $v$ varies as a function of the distance $x$ between the spheres, as:
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
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?
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 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?
The magnetic moment of atomic neon (in units of Bohr's magnetron) is