List of top Physics Questions

The ratio of thermal conductivity of two rods of different materials is \(4:3\). The two rods have same area of cross-section and same thermal resistance. The lengths of rods are in the ratio
The lengths of seconds pendulums on the surface of the earth and at an altitude '\(h\)' from the surface of the earth are \(l_s\) and \(l_h\) respectively. The radius of the earth is
A spherical object is falling under gravity through a viscous fluid. The sphere attains the terminal velocity when
Time period of a simple pendulum is \(T_1\) when on the earth's surface and \(T_2\) when taken to a height '2R' above the earth's surface, where 'R' is the radius of the earth. The ratio \(T_1:T_2\) is
A solid cylinder and a solid sphere having the same mass and radius roll down on the same smooth inclined plane. The ratio of the acceleration of the cylinder \((a_c)\) to that of the sphere \((a_s)\) is
The radius of gyration K of a hollow sphere of mass M and radius R about an axis XY is equal to R as shown in figure. The distance of that axis from the center of the sphere is h. The value of h is
The pressure at half the depth of a lake is equal to two-third pressure at the bottom of the lake. So the depth 'h' of the lake is (\(ρ\) = density of water in the lake, \(g\) = acceleration due to gravity, \(P_0\) = atmospheric pressure).
A body moves along a circular path of diameter \(30 \text{cm}\). It starts from one end of diameter, moves along the circular path and reaches the other end of diameter in 3 second. The angular speed of the body in radian per second is
The angular momentum of a rotating body is 'L'. When the frequency of rotating body is tripled and its kinetic energy is made one-third, the new angular momentum becomes
A block of mass M is lying on a horizontal frictionless surface. One end of the uniform rope of half the mass of the block is fixed to the block which is pulled in the horizontal direction by applying a force F at the other end. The tension in the middle of the rope will be
If two resistors of resistances have values \(R_1 = (350\pm 3) \Omega\) and \(R_2 = (140\pm 4) \Omega\). The percentage error for the sum and difference of \(R_1\) and \(R_2\) are respectively
The angle made by vector \(\overset{⃗}{A} = 2\hat{i}+3\hat{j}\) with x-axis and that with y-axis are respectively.
The activity of a radioactive sample is measured as \(N_0\) counts per minute at time \(t = 0\) and \(\frac{N_0}{e}\) counts per minute at time \(t = 3\) minute. The time (in minute) in which the activity reduces to half the value, is
In common emitter configuration of transistor amplifier, \(r_i\), \(R_L\) and \(β\) represent the input resistance, load resistance and the a.c. current gain respectively. The voltage gain \(A_V\) and power gain \(A_P\) are represented in magnitude respectively by
A semiconductor X is made by doping a germanium crystal with indium \((Z = 49)\). A second semiconductor Y is made by doping germanium crystal with arsenic \((Z = 33)\). Both are joined end to end and connected to a battery as shown. Which of the following statements is correct?
In the following digital circuit, the output 'Y' will be '1' (one) for inputs 'A' and 'B' having values
In Bohr's atomic model, the energy of the electron is 'E' in the second orbit of hydrogen atom. So the energy of the electron in the third orbit of helium atom \((Z = 2)\) will be
For obtaining maximum contrast between the bright and dark fringes in an interference pattern, the intensities of the two light coherent sources should be
A ray of light incident on one face of an equilateral glass prism having refractive index \(\sqrt{2}\), produces the emergent ray which just grazes along the adjacent face. The value of angle of incidence is \((sin90^{\circ} = 1)\)
\((sin30^{\circ} = \frac{1}{2})(sin45^{\circ} = \frac{1}{\sqrt{2}})\)
An unpolarised light of intensity \(64\text{ Wm}^{-2}\) passes through three polarizers successively such that the transmission axis of last polarizer is crossed with the first. The intensity of the emerging light is \(6\text{ Wm}^{-2}\). The angle between the transmission axis of the first two polarizers is
The ratio of the accelerating potentials required to accelerate (i) an \(α\)-particle and (ii) a proton to have the same de Broglie wavelength associated with them is
(mass of \(α\) - particle = \(6.4\times 10^{-27}\) kg, mass of proton = \(1.6\times 10^{-27}\) kg)
In Young's experiment, the intensity ratio of the maxima and minima in an interference pattern produced by two coherent sources is \(36:1\). The ratio of the amplitudes of the two individual sources will be
In photoelectric effect, keeping the frequency of incident radiation and accelerating potential fixed, if the intensity of incident light is increased,
In LCR circuit, at a particular angular frequency the capacitive reactance and inductive reactance is same. If the angular frequency is doubled, the ratio of the reactance of the capacitor to that of the inductor will be
In a series LCR circuit alternating e.m.f. and current are given by the equations \(V = V_0sin(ωt)\) and \(I = I_0sin(ωt+\frac{π}{3})\) respectively. The average power dissipated in the circuit over one cycle of a.c. is \((cos60^{\circ} = 0.5)\)