A copper block of mass 2 kg is heated from 20°C to 100°C. If the specific heat capacity of copper is $ 400 \, \text{J/kg°C} $, how much heat energy is absorbed by the block? (Assume no phase change occurs.)

A 200 g sample of water at 80°C is mixed with 100 g of water at 20°C. Assuming no heat loss to the surroundings, what is the final temperature of the mixture?

A metal plate of area 10^-2m² rests on a layer of castor oil, 2 × 10^-3m thick, whose viscosity coefficient is 1.55 Ns/m². The approximate horizontal force required to move the plate with a uniform speed of 3 × 10^-2ms^-1 is:

The elastic potential energy of a strained body is:

What will be the acceleration due to gravity at a depth $ d $, where $ g $ is the acceleration due to gravity on the surface of the Earth?

One main scale division of a vernier caliper is equal to $ m $ units. If the $ m $ divisions of the main scale coincide with the $ (n + 1)^{\text{th}} $ division of the vernier scale, the least count of the vernier caliper is:

Identify the correct output signal $ Y $ in the given combination of gates for the given inputs $ A $ and $ B $ shown in the figure.

The atomic mass of $^{6}C^{12}$ is 12.000000 u and that of ${}^{6}C^{13}$ is 13.003354 u. The required energy to remove a neutron from ${}^{6}C^{13}$, if the mass of the neutron is 1.008665 u, will be:

The minimum excitation energy of an electron revolving in the first orbit of hydrogen is:

The ratio of the shortest wavelength of the Balmer series to the shortest wavelength of the Lyman series for the hydrogen atom is:

Which of the following transitions of He$^+$ ion will give rise to a spectral line that has the same wavelength as the spectral line in a hydrogen atom?

The acceptor level of a p-type semiconductor is $ 6 $ eV. The maximum wavelength of light which can create a hole would be: Given $ hc = 1242 $ eV nm.

Which figure shows the correct variation of applied potential difference ($V$) with photoelectric current ($I$) at two different intensities of light ($I_1<I_2$) of same wavelengths:

When a light ray incidents on the surface of a medium, the reflected ray is completely polarized. Then the angle between reflected and refracted rays is:

The property of light which cannot be explained by Huygen's construction of a wavefront is:

A microwave of wavelength 2.0 cm falls normally on a slit of width 4.0 cm. The angular spread of the central maxima of the diffraction pattern obtained on a screen 1.5 m away from the slit will be:

In YDSE, monochromatic light falls on a screen 1.80 m from two slits separated by 2.08 mm. The first and second order bright fringes are separated by 0.553 mm. The wavelength of light used is:

If the distance between an object and its two times magnified virtual image produced by a curved mirror is 15 cm, the focal length of the mirror must be: