List of top Physics Questions

At the first minimum adjacent to the central maximum of a single-slit diffraction pattern, the phase difference between the Huygen's wavelet from the edge of the slit and the wavelet from the midpoint of the slit is
An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field produced at the centre has magnitude
Which logic gate is represented by the following combination of logic gates ?
The dimensions of Stefan?? constant are
With what maximum acceleration can a fireman slide down a rope whose breaking strength is two third of his weight?
Two particles A and B, move with constant velocities $\vec{v_1}$ and $\vec{v_2}$. At the initial moment their position vectors are $\vec{r_1}$, and $\vec{r_2}$ respectively. The condition for particles A and B for their collision is
The electric field in a certain region is acting radially outward and is given by E = Ar. A charge contained in a sphere of radius 'a' centred at the origin of the field, will be given by
The Young's modulus of steel is twice that of brass. Two wires of same length and of same area of cross section, one of steel and another of brass are suspended from the same roof. If we want the lower ends of the wires to be at the same level, then the weights added to the steel and brass wires must be in the ratio of
In an astronomical telescope in normal adjustment a straight black line of length $L$ is drawn on inside part of objective lens. The eye-piece forms a real image of this line. The length of this image is $I$ . The magnification of the telescope is
A rod of weight W is supported by two parallel knife edges A and B and is in equilibrium in a horizontal position. The knives are at a distance d from each other. The centre of mass of the rod is at distance a from A. The normal reaction on A is
Two springs of spring constant $1500\, Nm^{ - 1} \, and \, 3000\, Nm ^{-1}$ respectively are stretched with the same force. They will have potential energy in ratio
A photoelectric surface is illuminated successively by monochromatic light of wavelength $? $ and If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface of the material is (h = Planck's constant, c = speed of light)
The coefficient of performance of a refrigerator is $5$. If the temperature inside freezer is $-20^{\circ }C, $ the temperature of the surroundings to which it rejects heat is
The ratio of the specific heats $\frac{C_P}{C_V} = \gamma$ in terms of degrees of freedom (n) is given by :
The two ends of a metal rod are maintained at temperatures 100$^{\circ}$C and 110$^{\circ}$C. The rate of heat flow in the rod is found to be 4.0 J/s. If the end are maintained at temperatures 200$^{\circ}$C and 210$^{\circ}$C, the rate of heat flow will be
An experiment takes $10\, min$ to raise the temperature of water in a container from $0^{\circ} C$ to $100^{\circ} C$ and another $55\, min$ to convert it totally into steam by a heater supplying heat at a uniform rate. Neglecting the specific heat of the container and taking specific heat of water to be $1\, cal / g { }^{\circ} C$, the heat of vaporisation according to this experiment will come out to be
On a frictionless surface, a block of mass $M$ moving at speed $v$ collides elastically with another block of same mass $M$ which is initially at rest. After collision the first block moves at an angle $\theta$ to its initial direction and has a speed $\frac{v}{3}$. The second block's speed after the collision is
A rocket is launched vertically upward from the surface of the earth with an initial velocity of $ 10 \,km/s $ . If the radius of the earth is $ 6400 \,km $ and atmospheric resistance is negligible. Find the distance above the surface of the earth that the rocket will go.
A solid sphere is rolling down an inclined plane. Then, the ratio of its translational kinetic energy to its rotational kinetic energy is
In a cyclic process, the change in the internal energy of a system over one complete cycle
Consider boiling water converting into steam. Under this condition, the specific heat of water is
In an $n-p-n$ transistor, $p$ is
A satellite revolves around the earth of radius $R$ in a circular orbit of radius $3R.$ The percentage increase in energy required to lift it to an orbit of radius $5R$ is
Which of the following is incorrect about sky waves?
Which of the following is correct statement about the magnitude of the acceleration $a$ of the particle executing simple harmonic motion?