COMEDK 2024 Evening Shift

When an A.C. source is connected to a inductive circuit,

In the \(\mathrm{A} . \mathrm{C}\). circuit given below, voltmeters \(\mathrm{V}_1\) and \(\mathrm{V}_2\) read \(100 \mathrm{~V}\) each. Find the reading of the voltmeter \(\mathrm{V}_3\) and the ammeter \(\mathrm{A}\).

The distance of closest approach when an alpha particle of kinetic energy \(6.5 \mathrm{~MeV}\) strikes a nucleus of atomic number 50 is

The binding energy per nucleon for \(\mathrm{C}^{12}\) is \(7.68 \mathrm{~MeV}\) and that for \(\mathrm{C}^{13}\) is \(7.47 \mathrm{~MeV}\). The energy required to remove a neutron from \(\mathrm{C}^{13}\) is

If an electron in a hydrogen atom jumps from the third orbit to the second orbit, it emits a photon of wavelength \(\lambda\). When it jumps from the second to the first orbit, the corresponding wavelength of the photon will be

An electron has a mass of \(9.1 \times 10^{-31} \mathrm{~kg}\). It revolves round the nucleus in a circular orbit of radius \(0.529 \times 10^{-10} \mathrm{~m}\) at a speed of \(2.2 \times 10^6 \mathrm{~ms}^{-1}\). The magnitude of its angu...

\(\text { If the nuclear radius of }{ }^{27} \mathrm{Al} \text { is } 3.6 \text { fermi, the nuclear radius of }{ }^{125} \mathrm{Fe} \text { is }\)

A parallel plate capacitor having a dielectric constant 5 and dielectric strength \(10^6 \mathrm{~V} \mathrm{~m}^{-1}\) is to be designed with voltage rating of \(2 \mathrm{~kV}\). The field should never exceed \(10 \%\) of its dielectric s...

Figure below shows a network of resistors, cells, and a capacitor at steady state.

What is the current through the resistance 4 \(\Omega\) ?

The figure shows a network of five capacitors connected to a 20 V battery. Calculate the charge acquired by each 10 \(\mu\)F capacitor.

A ball is moving in a circular path of radius \(5 \mathrm{~m}\). If tangential acceleration at any instant is \(10 \mathrm{~ms}^{-2}\) and the net acceleration makes an angle of \(30^{\circ}\) with the centripetal acceleration, then, the in...

The resistance of a \(10 \mathrm{~m}\) long wire is \(10 \Omega\). Its length is increased by \(25 \%\) by stretching the wire uniformly. The new resistance is

A voltmeter of resistance \(1000 \Omega .0 .5 \mathrm{~V} /\) div is to be converted into a voltmeter to make it to read \(=1 \mathrm{~V} / \mathrm{div}\). The value of high resistance to be connected in series with it is

Three bulbs of \(40 \mathrm{~W}, 60 \mathrm{~W}\), and \(100 \mathrm{~W}\) are arranged in series with a \(220 \mathrm{~V}\) source. The maximum light is obtained from

Four resistors, each of resistance R, are connected as shown in the figure below.

A photon emitted during the de-excitation of electron from a state \(\mathrm{n}\) to the second excited state in a hydrogen atom, irradiates a metallic electrode of work function \(0.5 \mathrm{~eV}\), in a photocell, with a stopping voltage...

A particle of mass \(2 \mathrm{mg}\) has the same wavelength as a neutron moving with a velocity of \(3 \times 10^5 \mathrm{~ms}^{-1}\). The velocity of the particle is (mass of neutron is \(1.67 \times 10^{-27} \mathrm{Kg}\))

The temperature of a wire is doubled. The Young's modulus of elasticity

A conducting circular loop is placed in a uniform magnetic field \(\mathrm{B}=0.125 \mathrm{~T}\) with its plane perpendicular to the loop. If the radius of the loop is made to shrink at a constant rate of $$2 \mathrm{~mm} \mathrm{~s}^{-1}$...

A transformer of \(100 \%\) efficiency has 200 turns in the primary and 40000 turns in the secondary. It is connected to a \(220 \mathrm{~V}\) main supply and secondary feeds to a \(100 \mathrm{~K} \Omega\) resistance. The potential differe...

The magnetic flux linked with a coil is given by the equation: \(\phi=8 t^2+t+10\). The e.m.f. induced in the coil in the \(3^{\text {rd }}\) second will be

The current in a coil changes steadily from \(3 \mathrm{~A}\) to \(5 \mathrm{~A}\) in \(0.2 \mathrm{~s}\) when an emf of \(2 \mu \mathrm{V}\) is induced in it. The self-inductance of the coil is

Column - I lists the waves of the electromagnetic spectrum. Column - II gives approximate frequency range of these waves. Match Column - I and Column - II and choose the correct match from the given choices.

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Two point charges \(\mathrm{M}\) and \(\mathrm{N}\) having charges \(+q\) and \(-q\) respectively are placed at a distance apart. Force acting between them is \(\mathrm{F}\). If \(30 \%\) of charge of \(\mathrm{N}\) is transferred to $$\mat...

If 216 drops of the same size are charged at \(200 \mathrm{~V}\) each and they combine to form a bigger drop, the potential of the bigger drop will be

A neutral water molecule is placed in an electric field \(E=2.5 \times 10^4 \mathrm{NC}^{-1}\). The work done to rotate it by \(180^{\circ}\) is \(5 \times 10^{-25} \mathrm{~J}\). Find the approximate separation of centre of charges.

Three point charges are located on a circular arc at \(\mathrm{A}, \mathrm{B}\) and \(\mathrm{C}\) as shown in the figure below. The total electric field at the centre of the \(\operatorname{arc}(\mathrm{C})\) is

What is the relation obeyed by the angles of contact \(\theta_1, \theta_2\) and \(\theta_3\) of 3 liquids of different densities \(P_1, P_2\) and \(P_3\) respectively \((\mathrm{P}_1 < \mathrm{P}_2 < \mathrm{P}_3\)) when they rise to the sa...

The acceleration due to gravity at pole and equator can be related as

A satellite is revolving around the earth in a circular orbit with kinetic energy of \(1.69 \times 10^{10} \mathrm{~J}\). The additional kinetic energy required for just escaping into the outer space is

The coefficient of volume expansion of glycerine is \(49 \times 10^{-5} \mathrm{~K}^{-1}\). The percentage change in its density for a \(50^{\circ} \mathrm{C}\) rise in temperature is

The latent heat of vaporisation of water is \(2240 \mathrm{~J}\). If the work done in the process of vaporisation of \(1 \mathrm{~g}\) is \(168 \mathrm{~J}\), the increase in internal energy is

Internal energy of \(\mathrm{n}_1\) moles of hydrogen at temperature T is equal to internal energy of \(\mathrm{m}_2\) moles of helium at temperature 2T. The ratio \(\frac{n_1}{n_2}\) is

A cylinder of fixed capacity 44.81 contains hydrogen gas at STP. What is the amount of heat needed to raise the temperature of the gas in the cylinder by \(20^{\circ} \mathrm{C}\) ? ($$R=8.31 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$...

Action and reaction can never balance out because

A body initially at rest undergoes rectilinear motion. The forcetime (F-t) graph for the motion of the body is given below. Find the linear momentum gained by the body in \(2 \mathrm{~s}\).

For a paramagnetic material, the dependence of the magnetic susceptibility \(\chi\) on the absolute temperature is given as

A bar magnet is held perpendicular to a uniform field. If the couple acting on the magnet is to be halved, by rotating it, the angle by which it is to be rotated is

A cricketer of height \(2.5 \mathrm{~m}\) throws a ball at an angle of \(30^{\circ}\) with the horizontal such that it is received by another cricketer of same height standing at a distance of \(50 \mathrm{~m}\) from the first one. The maxi...

A wire of length \(2 \mathrm{~m}\) carries a current of \(1 \mathrm{~A}\) along the \(\mathrm{x}\) axis. A magnetic field \(B=B_0(i+j+k)\) tesla exists in space.
The magnitude of magnetic force on the wire is

A current I flows in an infinitely long wire with cross section in the form of semi-circular ring of radius \(1 \mathrm{~m}\). The magnitude of the magnetic induction along its axis is

A negative charge particle is moving upward in a magnetic field which is towards north. The particle is deflected towards

When a biconvex lens of glass of refractive index 1.5 is dipped in a liquid, it acts like a plane sheet of paper.
This means the refractive index of the liquid is

A hollow prism is filled with water and placed in air. It will deviate the incident rays

A telescope has an objective of focal length \(60 \mathrm{~cm}\) and eyepiece of focal length \(5 \mathrm{~cm}\). The telescope is focussed for least distance of distinct vision \(300 \mathrm{~cm}\) away from the object. The magnification p...

Figure below shows a lens of refractive index, \(\mu=1.4\). \(C_1\) and \(C_2\) are the centres of curvature of the two faces of the lens of radii of curvature \(4 \mathrm{~cm}\) and \(8 \mathrm{~cm}\) respectively.

The lens behaves as a

Joule second is the unit of

A solid cylinder of mass \(2 \mathrm{~kg}\) and radius \(0.2 \mathrm{~m}\) is rotating about its own axis without friction with angular velocity \(5 \mathrm{~rad} \mathrm{s}^{-1}\). A particle of mass \(1 \mathrm{~kg}\) moving with a veloci...

The conductivity of a semiconductor increases with increase in temperature because
A) number density of free current carriers increases
B) relaxation time increases
C) both number density of carriers and relaxation time increase
D) number d...

The output of the given circuit is
A. Negatively rectified half wave
B. Positively rectified half wave
C. Negatively rectified full wave
D. Zero all times