COMEDK 2020

A compound slab is made of two parallel plates
of copper and brass of the same thickness and
having thermal conductivities in the ratio 4 : 1.
The free face of copper is at 0\(^\circ\)C. The
temperature of the interface is 20\(^\circ\)C. Wh...

In mm\(^3\) of a gas is compressed at 1 atmospheric pressure and temperature 27\(^\circ\)C to 627\(^\circ\)C. What is the final pressure under adiabatic condition?
(\(\gamma\) for the gas = 1.5)

If sink is at a temperature of \(-39\Upsilon\)C and source at 0\(^\circ\)C, then efficiency will be

Equal volumes of two gases, having their
densities in the ratio of 1 : 16 exert equal
pressures on the walls of two containers. The
ratio of their rms velocities \(\left(\frac{c_1}{c_2}\right)\)

A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio \(C_p/C_V\) of the mixture is

Which of the following laws of Physics is valid
across all domains of nature?

A body under the action of a force \(F = 6\widehat i - 8\widehat j + 10\widehat k\), acquires an acceleration of 1 m/s2. The mass of this body must be

The intensity of magnetic field due to an isolated pole of strength \(m_p\) at a point distant \(r\) from it will be

The angle which the total magnetic field of
earth makes with the surface of the earth is
called

The angle of dip of at a place where horizontal
and vertical components of earth’s magnetic
field are equal is

A body is projected vertically upwards. The
times corresponding to height \(h\), while
ascending and while descending are \(t_1\) and \(t _2\) ,
respectively. Then, the velocity of projection is
(\(g\) is acceleration due to gravity)

A particle shows distance-time curve as given in
this figure. The maximum instantaneous
velocity of the particle is around the point

An electron moves with speed of 2 \(\times\) 10\(^5\) m/s along the positive x-direction in a magnetic field \(B = (\widehat i - 4\widehat j - 3\widehat k)\,T\). The magnitude of the force (in N) experienced by the electron is

A horizontal overhead power line carries a
current of 90 A in East to West direction. What
is the magnitude and direction of the magnetic
field due to the current, 1.5 m below the line?

A moving coil galvanometer has 28 turns and area of coil is \(4\times 10^{-2}\) m\(^2\). If the magnetic field is 0.2 T, then to increase the sensitivity by 25% without changing area and field, the number of turns should be changed to

The particle that cannot be accelerated by a cyclotron is

A convex lens is made of 3 layers of glass of 3 different materials as in the figure.

A point object is placed on its axis. The number
of images of the object are

A ray of light suffers minimum deviation in
equilateral prism P. Additional prisms Q and R
of identical shape and of same material as that of
P are now combined as shown in figure. The ray
will now suffer

Four particles each of the mass m are placed at
the corners of a square of side length \(l\). The
radius of gyration of the system about an axis
perpendicular to the square and passing
through its centre is

The masses of 200 g and 300 g are attached to
the 20 cm and 70 cm marks of a light meter rod,
respectively. The moment of inertia of the
system about an axis passing through 50 cm
mark is

When a \(p\)-\(n\) junction diode is connected in forward bias, its barrier potential

A particle executes a linear SHM with an
amplitude of 4 cm. At the mean position the
velocity of the particle is 10 cm/s. What is the
displacement of the particle when its speed
becomes 5 cm/s?

Suppose refractive index \(\alpha\) is given as \(\alpha = A + {B \over {{\lambda ^2}}}\), where A and B are constants and \(\lambda\) is wavelength, then dimensions of B are same as that of

A particle starts moving from point (2, 10, 1). Displacement for the particle is \(8\widehat i - 2\widehat j + \widehat k\). The final coordinates of the particle is

Two identical light waves, propagating in the
same direction, have a phase difference \(\delta\). After
they superpose the intensity of the resulting
wave will be proportional to

A plastic sheet (refractive index = 1 6. ) covers one
slit of a double slit arrangement for the Young’s
experiment. When the double slit is illuminated
by monochromatic light (wavelength = 5867 \(\mathop A\limits^o\)),
the centre of the sc...

The equation of a progressive wave can be given by \(y=15\sin(660\pi t-0.02\pi x)\) cm. The frequency of the wave is

A source of sound gives 5 beats per second, when sounded with another source of frequency 100 s\(^{-1}\). The second harmonic of the source, together with a source of frequency 205 s\(^{-1}\) gives 5 beats per second. What is frequency of t...

A particle of mass m is moving in a horizontal
circle of radius R under a centripetal force equal
to \(-\frac{A}{R^2}\) (A = constant). The total energy of the particle is

A force of 20 N is applied on a body of mass
5 kg resting on a horizontal plane. The body
gains a kinetic energy of 10 J after it moves a
distance 2 m. The frictional force is