MHT CET 2021 Physics Paper: 22 Sep, Shift 2

A step down transformer has turns ratio $20 : 1$. If $8\text{ V}$ is applied across $0.4\text{ ohm}$ secondary then the primary current will be

A step down transformer is used to reduce the main supply from '$V_1$ ' volt to '$V_2$ ' volt. The primary coil draws a current '$I_1$' $\text{A}$ and the secondary coil draws '$I_2$ ' A. $(I_1 < I_2)$. The ratio of input power to output power is

A capacitor of capacity '$C$' is charged to a potential '$V$'. It is connected in parallel to an inductor of inductance '$L$'. The maximum current that will flow in the circuit is

For the circuit shown below, instantaneous current through inductor '$L$' and capacitor '$C$' is respectively.

A parallel plate capacitor having plates of radius 6 cm has capacitance 100 pF. It is connected to 230 V a.c. supply with angular frequency 300 rad/s. The r.m.s. value of current is

In $n$th Bohr orbit, the ratio of the kinetic energy of an electron to the total energy of it, is

If '$E$' and '$L$' denote the magnitude of total energy and angular momentum of revolving electron in $n$th Bohr orbit, then

In parallel plate capacitor, electric field between the plates is '$E$'. If the charge on the plates is '$Q$' then the force on each plate is

Kirchhoff's current and voltage law are respectively based on the conservation of

In a potentiometer experiment, the balancing length for a cell is $240\text{ cm}$. On shunting the cell with a resistance of $2\ \Omega$, the balancing length becomes half the initial balancing length. The internal resistance of the cell is

The light of wavelength '$\lambda$' is incident on the surface of metal of work function $\phi$ and emits the electron. The maximum velocity of electron emitted is [$m =$ mass of electron and $h =$ Planck's constant, $c =$ velocity of light]

Photons of energy $10\text{ eV}$ are incident on a photosensitive surface of threshold frequency $2 \times 10^{15}\text{ Hz}$. The kinetic energy in $\text{eV}$ of the photoelectrons emitted is

[Planck's constant $h = 6.63 \times 10^{-34}\text{ Js}$ ]

When a photon enters glass from air, which one of the following quantity does not change?

the magnetic flux (in weber) in a closed circuit of resistance $20\,\Omega$ varies with time $t$ second according to equation $\phi = 5t^{2} - 6t + 9$. The magnitude of induced current at $t = 0.2$ second is

Two spherical conductors of radii $4\text{ cm}$ and $5\text{ cm}$ are charged to the same potential. If '$\sigma_1$' and '$\sigma_2$' be the respective values of the surface density of charge on the two conductors then the ratio $\sigma_1 : \sigma_2$ is

An electron of mass '$m$' and charge '$q$' is accelerated from rest in a uniform electric field of strength '$E$'. The velocity acquired by the electron when it travels a distance '$L$' is

Two particles $A$ and $B$ having same mass have charge $+q$ and $+4q$ respectively. When they are allowed to fall from rest through same electric potential difference, the ratio of their speeds '$V_A$' to '$V_B$' will become

At a height 'R' above the earth's surface the gravitational acceleration is (R = radius of earth, g = acceleration due to gravity on earth's surface)

Two satellites of same mass are launched in circular orbits at heights '$R$' and '$2R$' above the surface of the earth. The ratio of their kinetic energies is ($R =$ radius of the earth)

The rate of flow of heat through a copper rod with temperature difference $28^\circ\text{C}$ is $1400\text{ cal s}^{-1}$. The thermal resistance of copper rod will be

The emissive power of sphere of area $0.04\text{ m}^{2}$ is $0.7\text{ k cal s}^{-1}\text{ m}^{-2}$. The amount of heat radiated in 20 second is

An ideal gas having molar mass '$M_0$', has r.m.s. velocity 'V' at temperature 'T'. Then

The relative permeability of iron is 2000. Its absolute permeability in SI unit will be $(\frac{\mu_0}{4\pi} = 10^{-7}$SI unit$)$

A driver applies the brakes on seeing the red traffic signal $400\text{ m}$ ahead. At the time of applying the brakes, the vehicle was moving with $15\text{ m/s}$ and retarding at $0.3\text{ m/s}^2$. The distance covered by the vehicle from the traffic light 1 minute after the application of brakes is

The magnetic field inside a current carrying toroidal solenoid is $0.2\text{ mT}$. What is the magnetic field inside the toroid if the current through it is tripled and radius is made $\frac{1}{3}$rd?

A particle having a charge $100e$ is revolving in a circular path of radius $0.8\text{ m}$ with 1. r.p.s The magnetic field produced at the centre of the circle in SI unit is $(\mu_0 =$ permeability of vacuum, $e = 1.6 \times 10^{-19}\text{ C})$

Two radioactive materials $X_1$ and $X_2$ have decay constants '$5\lambda$' and '$\lambda$' respectively. Initially, they have the same number of nuclei. After time '$t$', the ratio of number of nuclei of $X_1$ to that of $X_2$ is $\frac{1}{e}$. Then $t$ is equal to

A body of mass '$m$' performs linear S.H.M. given by equation $x = P\sin\omega t + Q\sin\left(\omega t + \frac{\pi}{2}\right)$. The total energy of the particle at any instant is

'$n$' waves are produced on a string in 1 second. When the radius of the string is doubled, keeping tension same, the number of waves produced in 1 second for the same harmonic will be

A particle connected to the end of a spring executes S.H.M. with period '$T_1$'. While the corresponding period for another spring is '$T_2$'. If the period of oscillation with two springs in series is 'T', then

An object is located on a wall, its image of equal size is to be obtained on a parallel wall with the help of a convex lens. The lens is placed at a distance '$d$' in front of the second wall. The required focal length of the lens is

The critical angle for light going from medium '$x$' to medium '$Y$' is $\theta$. The speed of light in medium '$x$' is '$V_x$'. The speed of light in medium '$Y$' is

A particle with position vector$\vec{r}$has a linear momentum $\vec{P}$. Which one of the following statements is true in respect of its angular momentum 'L' about the origin?

A child is standing with folded hands at the centre of the platform rotating about its central axis. The kinetic energy of the system is '$K$'. The child now stretches his arms so that the moment of inertia of the system becomes double. The kinetic energy of the system now is

Two rings of radius 'R' and 'nR' made of same material have the ratio of moment of inertia about an axis passing through its centre and perpendicular to the plane is $1 : 8$. The value of '$n$' is (mass per unit length $= \lambda$)

Choose the correct statement. In semiconductors valance band and conduction band

For a common-emitter amplifier, the voltage gain is 40. Its input and output impedances are $100\ \Omega$ and $400\ \Omega$, respectively. The power gain of the CE amplifier will be

Which of the following gates will give an output '1' for the given inputs?

A needle is $7\text{ cm}$ long. Assuming that the needle is not wetted by water, what is the weight of the needle, so that it floats on water?

$[T =$ surface tension of water $= 70\,\frac{\text{dyne}}{\text{cm}}]$

[acceleration due to gravity $= 980\text{ cm s}^{-2}$]

If the pressure of an ideal gas is decreased by $10\%$ isothermally, then its volume will

The change in internal energy of the mass of a gas, when the volume changes from '$V$' to '$2V$' at constant pressure 'P' is ($\gamma =$ Ratio of Cp to Cv)

An ideal gas at $27^\circ\text{C}$ is compressed adiabatically to $(8/27)$ of its original volume. If ratio of specific heats, $\gamma = 5/3$ then the rise in temperature of the gas is

If the terminal speed of a sphere A [density $\rho_{\mathrm{A}} = 7.5\text{ kg m}^{-3}$ ] is $0.4\text{ ms}^{-1}$, in a viscous liquid [density $\rho_{\mathrm{L}} = 1.5\text{ kg m}^{-3}$ ], the terminal speed of sphere B [density $\rho_B = 3\text{ kg m}^{-3}$ ] of the same size in the same liquid is

A ball rises to the surface of a liquid with constant velocity. The density of the liquid is four times the density of the material of the ball. The viscous force of the liquid on the rising ball is greater than the weight of the ball by a factor of

A tuning fork of frequency '$n$' is held near the open end of tube which is closed at the other end and the lengths are adjusted until resonance occurs. The first resonance occurs at length $L_1$ and immediate next resonance occurs at length $L_2$. The speed of sound in air is

A glass tube of $1\text{ m}$ length is filled with water. The water can be drained out slowly from the bottom of the tube. If vibrating tuning fork of frequency $500\text{ Hz}$ is brought at the upper end of the tube then total number of resonances obtained are [Velocity of sound in air is $320\text{ ms}^{-1}$ ]

A sound wave of frequency $160\text{ Hz}$ has a velocity of $320\text{ m/s}$. When it travels through air, the particles having a phase difference of $90^\circ$, are separated by a distance of

If two sources emit light waves of different amplitudes then

In Young's double slit experiment using monochromatic light of wavelength '$\lambda$', the maximum intensity of light at a point on the screen is $K$ units. The intensity of light at point where the path difference is $\frac{\lambda}{3}$ is

$\left[\cos 60^\circ = \sin 30^\circ = \frac{1}{2}\right]$