List of top Questions asked in COMEDK UGET

When light wave passes from a medium of refractive index $ \mu $ to another medium of refractive index $ 2\mu $, the phase change occurs to the light is:

Which of the following statement is true regarding the centre of mass of a system?

An ideal diode is connected in series with a capacitor. The free ends of the capacitor and the diode are connected across a 220 V ac source. Now the potential difference across the capacitor is:

A coil offers a resistance of 20 ohms for a direct current. If we send an alternating current through the same coil, the resistance offered by the coil to the alternating current will be:

The current through a conductor is $ a $ when the temperature is 0°C. It is $ b $ when the temperature is 100°C. The current through the conductor at 220°C is:

Which of the following graph shows the variation of velocity with mass for the constant momentum?

The mass of a particle A is double that of particle B and the kinetic energy of B is $ \frac{1}{8} $ that of A. Then the ratio of the de-Broglie wavelength of A to that of B is:

Current flows through uniform, square frames as shown in the figure. In which case is the magnetic field at the centre of the frame not zero?

Steel is preferred to soft iron for making permanent magnets because,

A metal ball of mass m is projected at an angle $\theta$ with the horizontal with an initial velocity $ u $. If the mass and angle of projection are doubled keeping the initial velocity the same, the ratio of the maximum height attained in the former to the latter case is:

The threshold frequency for a metal surface is $ \nu_0 $. A photoelectric current $ I $ is produced when it is exposed to a light of frequency $ \frac{11}{6} \nu_0 $ and intensity $ I_0 $. If both the frequency and intensity are halved, the new photoelectric current $ I_1 $ will become:

In a single slit diffraction experiment, for slit width $ \alpha $, the width of the central maxima is $ \beta $. If we double the slit width then the corresponding width of the central maxima will be:

Find the binding energy of the tritium nucleus: [Given: mass of $ ^3H = 3.01605 \, u $; $ m_p = 1.00782 \, u $; $ m_n = 1.00866 \, u $]

Find the value of $ n $ in the given equation $ P = \rho v^n $ where $ P $ is the pressure, $ \rho $ is the density, and $ v $ is the velocity.

The power of a gun which fires 120 bullets per minute with a velocity 120 ms$^{-1}$ is: (given the mass of each bullet is 100 g)

A metallic rod of 2 m length is rotated with a frequency 100 Hz about an axis passing through the centre of the circular ring of radius 2 m. A constant magnetic field 2 T is applied parallel to the axis and perpendicular to the length of the rod. The emf developed across the ends of the rod is:

A body is moving along a circular path of radius $r$ with a frequency of revolution numerically equal to the radius of the circular path. What is the acceleration of the body if radius of the path is $\frac{5}{\pi} \, \text{m}?$

Around the central part of an air-cored solenoid of length 20 cm and area of cross section $1.4 \times 10^{-3} \, \text{m}^2$ and 3000 turns, another coil of 250 turns is closely wound. A current of 2 A in the solenoid is reversed in 0.2 s, then the induced emf produced is:

The ratio of the radii of the nucleus of two element X and Y having the mass numbers 232 and 29 is:

Two similar coils A and B of radius 'r' and number of turns 'N' each are placed concentrically with their planes perpendicular to each other. If $ I $ and $ 2I $ are the respective currents passing through the coils then the net magnetic induction at the centre of the coils will be:

If the earth has a mass nine times and radius four times that of planet X, the ratio of the maximum speed required by a rocket to pull out of the gravitational force of planet X to that of the earth is:

A ray of light travelling through a medium of refractive index $ \frac{5}{4} $ is incident on a glass of refractive index $ \frac{3}{2} $. Find the angle of refraction in the glass, if the angle of incidence at the given medium - glass interface is 30°

When a particular wave length of light is used, the focal length of a convex mirror is found to be 10 cm. If the wavelength of the incident light is doubled keeping the area of the mirror constant, the focal length of the mirror will be:

In the normal adjustment of an astronomical telescope, the objective and eyepiece are 32 cm apart. If the magnifying power of the telescope is 7, find the focal lengths of the objective and eyepiece.