List of top Questions asked in MHT CET- 2021

Two identical capacitors have the same capacitance $C$. One of them is charged to potential $V_1$ and the other to $V_2$. The negative ends of the capacitors are connected together. When positive ends are also connected, the decrease in energy of the combined system is
In Young's double slit experiment, in an interference pattern, a minimum is observed exactly in front of one slit. The distance between the two coherent sources is $d$ and $D$ is the distance between the source and screen. The possible wavelengths used are inversely proportional to
In the part of an a.c. circuit as shown, the resistance $R = 0.2\ \Omega$. At a certain instant $(V_A - V_B) = 0.5\text{ V}$, $I = 0.5\text{ A}$ and $\frac{\Delta I}{\Delta t} = 8\text{ A/s}$. The inductance of the coil is
In the circuit shown in the figure, a.c. source gives voltage $V = 20 \cos(2000t)$. Impedance and r.m.s. current respectively will be
Two identical ideal diodes are connected to an ammeter and a d.c source (1 volt) as shown. In which one of the following circuits, ammeter will not show any deflection?
A beam of light having wavelength $5400\text{ \AA}$ from a distant source falls on a single slit $0.96\text{ mm}$ wide and the resultant diffraction pattern is observed on a screen $2\text{ m}$ away. What is the distance between the first dark fringe on either side of the central bright fringe?
When an air column in a pipe open at both ends vibrates such that four antinodes and three nodes are formed, then the corresponding mode of vibration is
A current carrying loop is placed in a uniform magnetic field. The torque acting on the loop does not depend upon
For the output of the following logic circuit to be '1', the values of inputs A and B should be respectively
The work done in blowing a soap bubble of volume $V$ is $W$. The work required to blow a soap bubble of volume $2V$ is [$T$ = surface tension of soap solution]
In a photoelectric experiment, keeping the frequency of incident radiation and accelerating potential fixed, if the intensity of incident light is increased, then the
Let A, B and C be the three points in a uniform electric field $\vec{E}$ as shown. The electric potential is

Choose the correct answer from the options given below:
The ratio of maximum to minimum wavelength in Balmer series of hydrogen atom is
The electric field intensity on the surface of a charged solid sphere of radius $r$ and volume charge density $\rho$ is given by ($\varepsilon_0$ = permittivity of free space)
A step up transformer operates on $220\text{ V}$ and supplies current of $2\text{ A}$. The ratio of primary and secondary windings is $1 : 20$. The current in the primary is
A particle performing linear S.H.M. of amplitude $0.1\text{ m}$ has displacement $0.02\text{ m}$ and acceleration $0.5\text{ m/s}^2$. The maximum velocity of the particle in m/s is
A thin metal disc of radius $r$ floats on a water surface and bends the surface downwards along the perimeter making an angle $\theta$ with the vertical edge of the disc. If the weight of water displaced by the disc is $W$, the weight of the metal disc is [$T$ = surface tension of water]
A sonometer wire of length $25\text{ cm}$ vibrates in unison with a tuning fork. When its length is decreased by $1\text{ cm}$, $6$ beats are heard per second. What is the frequency of the tuning fork?
Two tuning forks of frequencies $320\text{ Hz}$ and $480\text{ Hz}$ are sounded together to produce sound waves. The velocity of sound in air is $320\text{ ms}^{-1}$. The difference between wavelengths of these waves is nearly
A p-n junction photodiode is fabricated from a semiconductor with a band gap of $2.5\text{ eV}$. It can detect a signal of wavelength [Planck's constant = $6.6 \times 10^{-34}\text{ Js}$, $c = 3 \times 10^8\text{ m/s}$, $e = 1.6 \times 10^{-19}\text{ C}$]
For a monoatomic gas, the work done at constant pressure is $W$. The heat supplied at constant volume for the same rise in temperature of the gas is
A monoatomic ideal gas initially at temperature $T_1$ is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature $T_2$ by releasing the piston suddenly. $L_1$ and $L_2$ are the lengths of the gas columns before and after the expansion respectively. Then $\frac{T_2}{T_1}$ is
The plates of a parallel plate capacitor of capacity $C_1$ are moved closer together until they are at half their original separation. The new capacitance $C_2$ is
A photon has wavelength $3\text{ nm}$, then its momentum and energy respectively will be $[h = 6.63 \times 10^{-34}\text{ Js}, c = 3 \times 10^8\text{ m/s}]$
The radii of curvature of both the surfaces of a convex lens of focal length $f$ and focal power $P$ are equal. One of the surfaces is made plane by grinding. The new focal length and focal power of the lens is respectively