COMEDK 2025 Evening Shift

A power transmission line feeds input power at 2200 V to a step-down transformer with its primary windings having 2000 turns. The output power is delivered at 220 V by the transformer. If the current in the primary of the transformer is 2 A...

In a pure inductive circuit, a sinusoidal voltage $V(t)=200 \sin 250 t$ is applied to a pure inductance of $\mathrm{L}=0.02 \mathrm{H}$. The current through the coil is:

A series LCR circuit having $\mathrm{R}=44 \Omega, \mathrm{~L}=2 \mathrm{H}$ and $\mathrm{C}=25 \mu \mathrm{~F}$ is connected to a variable frequency of 220 V . What is the average power transferred to the circuit in one complete cycle if t...

The instantaneous values of alternating current and voltages in a circuit are $\mathrm{I}=\frac{3}{\sqrt{2}} \sin (200 \pi t)$ ampere and $\mathrm{V}=\frac{3}{\sqrt{2}} \sin \left(200 \pi t+\frac{\pi}{6}\right)$ volt. What is the average po...

Select the correct statement from the following:

Which of the following is correct in the case of the Bohr model of atoms?
A. Predicts continuous emission spectra for all atoms
B. Assumes that the angular momentum of electrons is quantised
C. Predicts same emission spectrum for singly ion...

The minimum energy required by a hydrogen atom in ground state to emit radiation in Paschen series is nearly:

When ${ }^{10} \mathrm{~B}_5$ nuclei are bombarded by neutrons, one of the resultant nuclei is ${ }^7 \mathrm{Li}_3$. Then the emitted particle will be:

If the mass numbers of two nuclei are in the ratio $5: 2$ and their diameters are in ratio $2: 6$. Then their nuclear densities will be in the ratio

Radium having mass number 200 and binding energy per nucleon 5.6 MeV , splits into two fragments Cadmium of mass number 112 and Hassium of mass number 108. If the binding energy per nucleon for Cadmium and Hassium is approximately 8.0 MeV ,...

A capacitor of capacitance $4 \mu \mathrm{~F}$ is charged to a potential of 24 V and then connected in parallel to an uncharged capacitor of capacitance $6 \mu \mathrm{~F}$. The final potential difference across each capacitor will be:

A network of capacitors is as shown below. If the voltage supply is 100 V , find the energy stored in the $6 \mu \mathrm{~F}$ capacitor.

$C_1=3 \mu F, C_2=6 \mu F, C_3=3 \mu F$ and $C_4=4 \mu F$

Select the correct statement from the following: The position of the centre of mass of a system :

The velocity - mass graph of body with constant linear momentum is represented by the graph:

A point marked on a ring of radius 2 cm is in contact with a horizontal plane. Now the ring is rolled forward half a revolution along the positive X - direction. Then the angle made by the displacement vector of the point with the X - axis ...

The resistance of a heating element is found to be $120 \Omega$ at room temperature which is $20^{\circ} \mathrm{C}$. If the temperature coefficient of the material of the resistor is $1.6 \times 10^{-4} C^{-1}$ and the resistance is found ...

A galvanometer having a resistance of $50 \Omega$ is shunted by a wire of resistance $10 \Omega$. If the total current is 2 A , the current passing through the shunt is:

The power dissipated across the $16 \Omega$ resistor in the circuit is 2 watts. The power dissipated in watt units across the $4 \Omega$ resistor is:

The net resistance between the points A and B in the circuit given below is:

A student measures the terminal potential difference $V$ of a cell of emf $\varepsilon$ and internal resistance $r$ as a function of the current I flowing through it. Which of the following graphs will give the values of emf $\varepsilon$ a...

The stopping potential when a metal surface is illuminated by light of wavelength $\lambda$ is 15 V . The stopping potential when the same surface is illuminated by light of wavelength $4 \lambda$ is 3 V . The ratio of threshold wavelength ...

A plot of kinetic energy of emitted photoelectrons from a metal versus the frequency of incident radiation gives a straight line, the intercept of which
A. Depends on the nature of the metal used
B. Depends on the intensity of radiation
C. ...

A wire of negligible mass having uniform area of cross section ' A ' and young modulus ' Y ' is used to suspend a point mass ' m '. The point mass executes simple harmonic motion in a vertical plane with a period ' T ', then the length of t...

Select the correct statement from the following:

A rectangular coil of 250 turns has an average area of $20 \mathrm{~cm} \times 15 \mathrm{~cm}$. The coil rotates with a speed of 60 cycles per second in a uniform magnetic field of $2 \times 10^{-2} \mathrm{~T}$ about an axis perpendicular...

A plane electromagnetic wave with frequency 40 MHz travels in free space. At a particular point in space and time, the magnetic field is $2 \times 10^{-8} T$. What will be the electric field at this point?

A bob of a simple pendulum has a mass of 4 g and a charge of $20 \mu \mathrm{C}$. If it is at rest in a uniform horizontal electric field of intensity $1000 \mathrm{Vm}^{-1}$, the angle that the pendulum makes with the vertical at equilibri...

Two electric dipoles of dipole moments $3.9 \times 10^{-30} \mathrm{Cm}$ and $5.2 \times 10^{-30} \mathrm{Cm}$ are placed in two different uniform electric fields of strengths $16 \times 10^4 \mathrm{NC}^{-1}$ and $4 \times 10^4 \mathrm{NC}...

A particle of mass 3 g and charge $60 \mu \mathrm{C}$ is released from rest in a uniform electric field of intensity $10^5 N C^{-1}$. If the value of kinetic energy attained by the particle after moving through a distance of 2 cm is $m \tim...

A uniformly charged conducting sphere of 0.2 m diameter has a surface charge density of $70 \mu \mathrm{Cm}^{-2}$. The electric flux leaving the surface of the sphere is:

Three charges, $Q,-q$ and $2 q$ are placed at the vertices of a right-angled isosceles triangle. What is the value of $q$ for the net electrostatic energy of the configuration to be zero?

In to a vessel containing pure water a clean glass tube of radius $3.6 \times 10^{-4} \mathrm{~m}$ is held vertically with 12 cm of the tube above the water level. Now the capillary tube is moved down in to the water so that only 2 cm of it...

The unit of universal gravitational constant is :

If the distance between the Sun and Earth is doubled, then the duration of the year on earth will be :
[Given actual duration of the year $=\mathbf{T}$ ]

The rate of heat conduction in the given two metal rods having the same length is found to be the same when the temperature difference between the ends is kept $30^{\circ} \mathrm{C}$ If the area of cross section of the first rod is $8 \tim...

The total number of degrees of freedom associated with $2 \mathrm{~cm}^3$ of Nitrogen gas at normal temperature and pressure is:
[Given Avogadro number as ' N ' ]

The rms velocity of the gas molecule at $327^{\circ} \mathrm{C}$ is same as the rms velocity of the oxygen molecules at $27^{\circ} \mathrm{C}$. If the molecular weight of oxygen is 32 then the molecular weight of the given gas molecule is:

A given volume of gas at NTP is allowed to expand 6 times of its original volume, first under isothermal condition and then under adiabatic condition. Which of the given statement is correct? [Given $\frac{c_p}{c_v}=\gamma=1.4$ ]

A body of mass 10 kg is moving up on an inclined plane of $30^{\circ}$ with an acceleration $2 \mathrm{~ms}^{-2}$. Find the force required, if the coefficient of friction between the object and the plane surface is $\frac{\sqrt{3}}{6}$, [gi...

A metal rod of susceptibility 799 is subjected to a magnetising field of $2000 \mathrm{Am}^{-1}$. The permeability of the material of the rod is: (Given $\mu_0=4 \pi \times 10^{-7} \mathrm{TmA}^{-1}$ )

A short bar magnet placed with its axis at $45^{\circ}$ with an external field of $400 \times 10^{-4} \mathrm{~T}$ experiences a torque of 0.024 Nm . If a solenoid of cross-sectional area $10^{-4} \mathrm{~m}^2$ and 500 turns replaces the s...

A boy is running along a straight horizontal road with a constant speed $5 \mathrm{~ms}^{-1}$. While running he throws a stone with a velocity $30 \mathrm{~ms}^{-1}$ at an angle $60^{\circ}$ with the horizontal. Then the time of flight of t...

Select the graph which represents the motion of a particle along a straight line with uniform acceleration.

A straight wire of mass 250 g and length 2.5 m carries a current of 4 A . It can be suspended in mid air by a uniform horizontal magnetic field of magnitude:

In a particular case X , a certain length of insulated copper wire is bent to form double loops of equal radii. In another case Y the same copper wire is bent to form three loops of equal radii. If the same steady current is passed through ...

A current carrying closed loop in the form of a right isosceles triangle XYZ is placed in a uniform magnetic field $B$ acting along $X Y$ of the loop. If the magnetic force on the arm $Y Z$ is $\sqrt{2} F$, then the force on the arm $X Z$ i...

A beam of incident parallel light falls on a diverging lens of focal length 20 cm in magnitude. If a converging lens of focal length 15 cm in magnitude is placed at a distance of 10 cm to the right of the diverging lens on the other side, t...

In the normal adjustment of an astronomical telescope, the objective and eyepiece are 36 cm apart. If the magnifying power of the telescope is 8 , find the focal lengths of the objective and eyepiece.

An object of height $h$ is placed midway between $f$ and $2 f$ in front of a biconvex lens. A real inverted image is captured on a screen placed a little beyond 2 f on the other side of the lens. If the whole arrangement is immersed in wate...

A plano-convex lens made of refractive index 1.5 and having radius of curvature $\mathrm{R}=4 \mathrm{~cm}$ fits exactly into a planoconcave lens made of refractive index 1.3 and having the same radius of curvature $R=4 \mathrm{~cm}$ such t...