COMEDK 2025 Afternoon Shift

The value of universal gravitational constant was first determined by

Two spherical planets P and Q have the same uniform density $\rho$, and masses Mp and $\mathrm{MQ}_{\mathrm{Q}}$ and surface areas A and 4 A respectively. Another spherical planet $R$ also has the same uniform density $\rho$, and its mass i...

The heat required to increase the temperature of 4 moles of a mono-atomic ideal gas from $273^{\circ} \mathrm{C}$ to $473^{\circ} \mathrm{C}$ at constant volume is

Rods $A$ and $B$ have their lengths in the ratio $1: 2$. Their thermal conductivities are $K_1$ and $K_2$ respectively. The temperatures at the ends of each rod are $\mathrm{T}_1$ and $\mathrm{T}_2$. If the rate of flow of heat through the ...

An ideal gas is expanding such that $P T^2=$ constant. The coefficient of volume expansion of the gas is

A monoatomic ideal gas, initially at temperature $T_1$, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature $\mathrm{T}_2$ by releasing the piston suddenly. If $L$ and $2 ...

A body weighing 125 kg just slides down a rough inclined plane that rises 1 m in every 2 m . What is the coefficient of friction?

For a short magnet, the magnetic field on the axial line at a distance 10 cm from its centre is $1.6 \mathrm{~m} \times 10^{-7} \mathrm{~T}$. What is the magnetic field on its equatorial line at the same distance 10 cm from its centre?

A car, starting from rest, accelerates at the rate (f) through a distance ( $S$ ), then continues at constant speed for some time $(t)$ and then decelerates at the rate $\frac{f}{2}$ to come to rest. If the total distance is $5 S$, then

A gun is used to fire a bullet at an angle of $30^{\circ}$ and at $60^{\circ}$ respectively. The ratios of heights and Ranges reached by the bullet are

In to a uniform transverse magnetic field, two charged particles having the same mass and charge enter and move in two different circular paths. The ratio of the radii of curvatures of the circular paths is $1: 4$. What would be the ratio o...

A rectangular coil of length 10 cm and breadth 9 cm carries a current of 10 A . A long straight conductor carrying a current of 20 A is placed 1 cm from the coil parallel to its length and in the same plane of the coil. What will be the net...

What is the kinetic energy of the electron in the nth level, moving in a plane under the influence of a magnetic field ' B '? [ m -mass of electron; h - Planck's constant; e- electronic charge]

Which physical quantity has the unit joule / tesla?

When a body of refractive index $\boldsymbol{\mu}=\mathbf{1 . 4}$ is put into a liquid, the body becomes invisible. What would be the refractive index of the medium?

A beam of light parallel to the principal axis of a concave and convex lens, first passes through the concave lens of focal length 0.5 m and then through the convex lens of focal length 1.75 m . If the lenses are placed 1.25 apart, which of...

A ray of light is travelling from glass of refractive index $\frac{3}{2}$ to water of refractive Index $\frac{4}{3}$. What is the minimum angle of incidence for which no light enters in to the water?

What is the velocity of light in vacuum if the velocity of light in a medium of refractive index 1.2 is ' v ' $\mathrm{ms}^{-1}$ ?

The focal lengths of the objective and eyepiece of a compound microscope are 1 cm and 10 cm respectively. Length of the tube is 25 cm . If the final image is formed at infinity , the magnifying power of the microscope is :

A bullet of momentum $p$ is fired into a door and gets embedded exactly at the center of the door. The door is 1.0 m wide and weighs 12 kg . It is hinged at one end and rotates about a vertical axis practically without friction. The angular...

What is the maximum wave length of EM radiation required to move an electron from the valance band to conduction band of a semiconductor? [Given :Energy gap $\mathrm{E}_{\mathrm{g}}=1.98 \times 10^{-19} \mathrm{~J}$; Planck's constant $h=6....

Diamond is considered as an insulator because

Three ideal diodes and resistors connected to the cell of negligible internal resistance is as shown. Find the current passing through the $10 \Omega$ resistor.

Time period of oscillation of a mass suspended from a spring is T . If the spring is cut into four equal parts and the same mass is suspended from one of the parts, the fractional change in time period is

In the expression $\mathrm{P}=\mathrm{El}^2 \mathrm{~m}^{-5} \mathrm{G}^{-2}$ where $\mathrm{E}, 1, \mathrm{~m}$ and G represent Energy, Angular Momentum, Mass and Gravitational Constant, the dimensions of P are

The square of resultant of two equal electric field vectors is three times their product. Angle between them is

In the Young's double slit experiment, when a monochromatic light is used, fringe width obtained is 1 mm . If the wave length is halved and the slit width is doubled, what will be the new fringe width?

A monochromatic light of wave length $6000^{\circ} \mathrm{A}$ is passed through two media A and B of thickness 10 cm and 16 cm respectively. The number of waves in $A$ is $\frac{1}{2}$ that of $B$. If the refractive index of $A$ is $\frac{...

An EM wave of frequency $5 \times 10^9 \mathrm{~Hz}$ falls normally on a rectangular slit of width 3 cm . What is the total angular width of the central maxima?

An open pipe is in second harmonic with frequency $f_1$. One end of the tube is closed and frequency is increased to $f_2$ and it resonates again with nth harmonic. For what value of n , the ratio of $\frac{f_1}{f_2}$ is $\frac{4}{5}$ ?