List of top Physics Questions

A particle executes simple harmonic motion represented by displacement function as x(t) = A sin($\omega$t+$\phi$). If the position and velocity of the particle at t = 0 s are 2 cm and 2$\omega$ cm s$^{-1}$ respectively, then its amplitude is $x\sqrt{2}$ cm where the value of x is ________.
The difference in the number of waves when yellow light propagates through air and vacuum columns of the same thickness is one. The thickness of the air column is ________ mm.
[Refractive index of air = 1.0003, wavelength of yellow light in vacuum = 6000 Å]
The water is filled upto height of 12 m in a tank having vertical sidewalls. A hole is made in one of the walls at a depth 'h' below the water level. The value of 'h' for which the emerging stream of water strikes the ground at the maximum range is ________ m.
The K$_\alpha$ X-ray of molybdenum has wavelength 0.071 nm. If the energy of a molybdenum atom with a K electron knocked out is 27.5 keV, the energy of this atom when an L electron is knocked out will be ________ keV. (Round off to the nearest integer)
[ h = $4.14 \times 10^{-15}$ eVs, c = $3 \times 10^8$ ms$^{-1}$ ]
A 100 $\Omega$ resistance, a 0.1 $\mu$F capacitor and an inductor are connected in series across a 250 V supply at variable frequency. Calculate the value of inductance of inductor at which resonance will occur. Given that the resonant frequency is 60 Hz.
An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3 eV. The proton captures the electron and forms a hydrogen atom in second excited state. The resulting photon is incident on a photosensitive metal of threshold wavelength 4000 Å. What is the maximum kinetic energy of the emitted photoelectron?
The maximum amplitude for an amplitude modulated wave is found to be 12 V while the minimum amplitude is found to be 3 V. The modulation index is 0.6x where x is ________ .
The resistance of a conductor at $15^\circ\text{C}$ is 16 $\Omega$ and at $100^\circ\text{C}$ is 20 $\Omega$. What will be the temperature coefficient of resistance of the conductor?
An object of mass 0.5 kg is executing simple harmonic motion. Its amplitude is 5 cm and time period (T) is 0.2 s. What will be the potential energy of the object at an instant t = T/4 starting from mean position. Assume that the initial phase of the oscillation is zero.
The planet Mars has two moons, if one of them has a period 7 hours, 30 minutes and an orbital radius of $9.0 \times 10^3$ km. Find the mass of Mars.
$\left\{ \text{Given } \frac{4\pi^2}{G} = 6 \times 10^{11} \text{ N}^{-1} \text{ m}^{-2} \text{ kg}^2 \right\}$
Two identical particles of mass 1 kg each go round a circle of radius R under the action of their mutual gravitational attraction. The angular speed of each particle is :
Two Carnot engines A and B operate in series such that engine A absorbs heat at $T_1$ and rejects heat to a sink at temperature T. Engine B absorbs half of the heat rejected by Engine A and rejects heat to the sink at $T_3$. When workdone in both the cases is equal, the value of T is :
An automobile of mass 'm' accelerates starting from origin and initially at rest, while the engine supplies constant power P. The position is given as a function of time by:
A physical quantity 'y' is represented by the formula $y = m^x r^{-4} g^p l^{3/2}$. If the percentage errors found in y, m, r, l and g are 18, 1, 0.5, 4 and p respectively, then find the value of x and p.
One mole of an ideal gas is taken through an adiabatic process where the temperature rises from $27^\circ\text{C}$ to $37^\circ\text{C}$. If the ideal gas is composed of polyatomic molecule that has 4 vibrational modes, which of the following is true?
[R = 8.314 J mol$^{-1}$ K$^{-1}$]
A raindrop with radius R=0.2 mm falls from a cloud at a height h=2000 m above the ground. Assume that the drop is spherical throughout its fall and the force of buoyancy may be neglected, then the terminal speed attained by the raindrop is :
[Density of water $f_w = 1000 \text{ kg m}^{-3}$ and Density of air $f_a = 1.2 \text{ kg m}^{-3}$, $g=10 \text{ m/s}^2$
Coefficient of viscosity of air $= 1.8 \times 10^{-5} \text{ Ns m}^{-2}$ ]
Consider the following statements :
A. Atoms of each element emit characteristics spectrum.
B. According to Bohr's Postulate, an electron in a hydrogen atom, revolves in a certain stationary orbit.
C. The density of nuclear matter depends on the size of the nucleus.
D. A free neutron is stable but a free proton decay is possible.
E. Radioactivity is an indication of the instability of nuclei.
Choose the correct answer from the options given below :
A particle of mass M originally at rest is subjected to a force whose direction is constant but magnitude varies with time according to the relation
$F = F_0 \left[1 - \left(\frac{t}{T}\right)^2\right]$
Where $F_0$ and T are constants. The force acts only for the time interval 2T. The velocity v of the particle after time 2T is:

Consider a water tank as shown in the figure. It's cross-sectional area is 0.4 m². The tank has an opening B near the bottom whose cross-section area is 1 cm². A load of 24 kg is applied on the water at the top when the height of the water level is 40 cm above the bottom, the velocity of water coming out the opening B is v ms\(^{-1}\). The value of v, to the nearest integer, is ________. [Take value of g to be 10 ms\(^{-2}\)] 

Consider a 72 cm long wire AB as shown in the figure. The galvanometer jockey is placed at P on AB at a distance x cm from A. The galvanometer shows zero deflection. The value of x, to the nearest integer, is ________. 

The typical output characteristics curve for a transistor working in the common-emitter configuration is shown in the figure. The estimated current gain from the figure is ________. 

The projectile motion of a particle of mass 5 g is shown in the figure.

The initial velocity of the particle is \(5\sqrt{2}\) ms\(^{-1}\) and the air resistance is assumed to be negligible. The magnitude of the change in momentum between the points A and B is x \(\times 10^{-2}\) kgms\(^{-1}\). The value of x, to the nearest integer, is ________.

Three rays (R, G, B) are incident on PQ... Refractive indices are 1.27, 1.42 and 1.49. The colour of the ray(s) emerging out of the face PR is: 

The velocity - displacement graph of a particle is shown in the figure.

The acceleration - displacement graph of the same particle is represented by: 

A solid cylinder of mass \(m\) is wrapped with an inextensible light string and is placed on a rough inclined plane as shown in the figure. The frictional force acting between the cylinder and the inclined plane is: [The coefficient of static friction, \(\mu_s\), is 0.4] (Figure: Cylinder on 60° incline with string wrapped parallel to the incline)