List of top Physics Questions

A source of sound is moving towards a stationary observer with velocity '\(V_S\)' and then moves away with velocity '\(V_S\)'. Assume that medium through which the sound waves travel is at rest. If 'V' is the velocity of sound and 'n' is the frequency emitted by the source then the difference between the apparent frequencies heard by the observer is

Initially, 'n' identical capacitors are joined in parallel, are charged to potential 'V'. Now they are separated and joined in series. Then

Three parallel plate air capacitors are connected in parallel. Each capacitor has plate area A/3 and separation between the plates is d, 2d and 3d respectively. The equivalent capacity of the combination is (\(ε_0\)-permittivity of free space)

If the radius of the spherical Gaussian surface is increased then the electric flux due to a point charge enclosed by the surface

Two uniform wires of same material are vibrating under the same tension. If the first overtone of the first wire is equal to the second overtone of the second wire and radius of first wire is twice the radius of second wire then the ratio of length of first to second wire is

A mass \(0.4\) kg performs S.H.M. with a frequency \(\frac{16}{π}\) Hz. At a certain displacement it has kinetic energy \(2\) J and potential energy \(1.2\) J. The amplitude of oscillation is

A mass attached to a spring performs S.H.M. whose displacement is \(x = 3\times 10^{-3}cos2πt\) m. The time taken to obtain maximum speed for the first time is (in s)

The closed and open organ pipe have same length and when they are vibrating simultaneously in first overtone produce \(3\) beats. The length of open pipe is made \((\frac{1}{3})^{rd}\) and closed pipe is made \(3\) times the original, the number of beats produced will be {neglect end correction}

The equation of a progressive wave is \(Y = 3sin[π(\frac{t}{3}-\frac{x}{5})+\frac{π}{4}]\) where X and Y are in metre and time in second. Which of the following is correct?

An oscillating pendulum suspended from the roof of a lift which is at rest has time period \(T_1\). When lift moves up with acceleration 'a' its time period is \(T_2\). When lift moves down with acceleration 'a' its time period is \(T_3\). The relation between \(T_1\), \(T_2\) and \(T_3\) is

A body cools in \(7\) minutes from \(60^{\circ}\)C to \(40^{\circ}\)C. What time (in minutes) does it take to cool from \(40^{\circ}\)C to \(28^{\circ}\)C, if its surrounding temperature is \(10^{\circ}\)C ? (Newton's law of cooling holds good)

An insulated container contains a monoatomic gas of molar mass 'm'. The container is moving with velocity 'V'. If it is stopped suddenly, the change in temperature of the gas is (R-gas constant)

A rigid diatomic gas undergoes adiabatic change. Its pressure P and temperature T are related as \(P\propto T^x\) where x is

If \(\Delta Q\) is the amount of heat supplied to 'n' moles of a rigid diatomic gas at constant pressure, \(\Delta U\) is the change in internal energy and \(\Delta W\) is the work done then \(\Delta W:\Delta U:\Delta Q\) is

Carnot engine operating between temperatures \(T_1\) and \(T_2\) has efficiency \(0.2\). When \(T_2\) is lowered by \(45\) K, its efficiency becomes \(0.5\). Temperatures \(T_1\) and \(T_2\) are respectively

For a gas, \(\frac{R}{C_v} = 0.4\) where R is the universal gas constant and \(C_v\) is the molar specific heat at constant volume. The gas is made up of molecules which are

Due to surface tension, the excess pressure inside a smaller drop is \(9\) units. If \(27\) smaller drops combine then excess pressure inside the bigger drop is

The density of a planet is three times that of earth and radius \(2.5\) times that of earth. If \(g_p\) and \(g_e\) represents acceleration due to gravity on planet and earth respectively then ratio \(g_p\) to \(g_e\) is

A liquid drop having surface energy E is sprayed into \(512\) droplets of the same size. Then the final surface energy is

In a capillary tube of radius 'R', a straight thin metal wire of radius 'r' is inserted symmetrically and one end of the combination is dipped vertically in water such that lower end of the capillary and thin wire are at same level. If 'T' is the surface tension of water and '\(ρ\)' is the density of water then the rise of water in the capillary is

The moment of inertia of a ring about an axis passing through its centre and perpendicular to its plane is I. It is rotating with angular velocity \(ω\). Another identical ring is gently placed on it so that their centres coincide. If both rings are rotating about the same axis then loss in kinetic energy is

Let M and L be the mass and length of thin uniform rod respectively. In first case, axis of rotation is passing through centre and perpendicular to length of rod. In second case axis of rotation is passing through one end and perpendicular to length of rod. The ratio of radius of gyration in first case to second case is

A mass M moving with velocity V along X-axis collides and sticks to another mass 2M which is moving along Y-axis with velocity 3V. The velocity of the combination, after the collision is

A quantity P is related as \(X^{-2}Y^{-3/2}Z^{2/5}\) where X,Y,Z are independent parameters which have fractional errors of \(0.1,0.2\) and \(0.5\) respectively in measurement. The maximum fractional error in P is

In non uniform circular motion, the ratio of radial acceleration to tangential acceleration is (V is the velocity, r is the radius and \(α\) is the angular acceleration)