List of top Questions asked in MHT CET- 2021

For a gas molecule with 6 degrees of freedom, which one of the following relations between gas constant '$R$' and molar specific heat '$C_v$' is correct?

A nucleus breaks into two nuclear parts, which have their velocity ratio $2 : 1$. The ratio of their nuclear radii will be

Let $W_1$ be the work done in blowing a soap bubble of radius $r$ from a soap solution at room temperature. The soap solution is now heated and a second soap bubble of radius $2r$ is blown from the heated soap solution. If $W_2$ is the work done in forming this second bubble, then

The permeability of a metal is $0.1256\ \text{T}\cdot\text{m}\cdot\text{A}^{-1}$. Its relative permeability will be ($\frac{\mu_0}{4\pi} = 10^{-7}\ \text{SI unit}$, $\pi = 3.14$)

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

A cylindrical rod has temperatures $\theta_1$ and $\theta_2$ at its ends. The rate of heat flow is $Q\ \text{J}\ \text{s}^{-1}$. All the linear dimensions of the rod are doubled while keeping the temperatures constant. What is the new rate of flow of heat?

Two concentric coplanar circular loops of radii $r_1$ and $r_2$ respectively carry currents $i_1$ and $i_2$ in opposite directions (one clockwise and other anticlockwise). The magnetic induction at the centre of the loops is half that due to $i_1$ alone at the centre. If $r_2 = 2r_1$, the value of $\frac{i_2}{i_1}$ is

The angular displacement of a body performing circular motion is given by $\theta = 5 \sin\left(\frac{\pi t}{6}\right)$. The angular velocity of the body at $t = 3\ \text{second}$ will be [$\sin\left(\frac{\pi}{2}\right) = 1$, $\cos\left(\frac{\pi}{2}\right) = 0$]

The frequency of the output signal of an LC oscillator circuit is $F\ \text{Hz}$ with a capacitance of $0.1\ \mu\text{F}$. If the value of the capacitor is increased to $0.2\ \mu\text{F}$, then the frequency of the output signal will be

When a battery is connected to the two ends of a diagonal of a square conductor frame of side $a$, the magnitude of magnetic field at the centre will be ($\mu_0 = $ permeability of free space)

A bob of a simple pendulum of mass $m$ is displaced through $90^\circ$ from its mean position and released. When the bob is at its lowest position, the tension in the string is

A car of mass $m$ moving with velocity $u$ on a straight road in a straight line, doubles its velocity in time $t$. The power delivered by the engine of a car for doubling the velocity is

Which of the following statements is true? ($\Delta U = $ increase in internal energy, $dW = $ work done by the system)
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A solid sphere of mass $M$ and radius $R$ is rotating about its diameter. A solid cylinder of same mass and same radius is also rotating about its geometrical axis with an angular speed twice that of the sphere. The ratio of the kinetic energy of rotation of the sphere to that of the cylinder is

If a current flowing in a coil is reduced to half of its initial value, the relation between the new energy ($E_2$) and the original energy ($E_1$) stored in the coil will be

If the temperature of the sun is doubled, the rate of energy received by the earth will be increased by a factor

Water rises in a capillary tube of radius $r$ up to a height $h$. The mass of water in the capillary is $m$. The mass of water that will rise in a capillary tube of radius $\frac{r}{3}$ will be

A sonometer wire resonates with a given tuning fork forming standing waves with five antinodes between the two bridges when a mass of $9\ \text{kg}$ is suspended from the wire. When this mass is replaced by a mass $M$, the wire resonates with the same tuning fork forming three antinodes for the same positions of the bridges. The value of '$M$' is

The critical angle for light going from medium A into medium B is $\theta$. The speed of light in medium A is $V_A$. What is the speed of light in medium B?

In a Wheatstone's bridge, three resistances $P$, $Q$ and $R$ are connected in the three arms and the fourth arm is formed by two resistances $S_1$ and $S_2$ connected in parallel. The condition for the bridge to be balanced is

Choose the FALSE statement from the following.

The mass of a planet is six times that of the earth. The radius of the planet is twice that of the earth. If the escape velocity from the earth is '$V_e$', then the escape velocity from the planet is

A biconvex lens ($R_1 = R_2 = 30\ \text{cm}$) has focal length equal to the focal length of a concave mirror. The radius of curvature of the concave mirror is [Refractive index of material of lens $= 1.6$]

In an a.c. circuit, a resistance $R = 40\ \Omega$ and an inductance '$L$' are connected in series. If the phase angle between voltage and current is $45^\circ$, then the value of the inductive reactance is ($\tan 45^\circ = 1$)

A mass $0.4\ \text{kg}$ performs S.H.M. with a frequency $\frac{16}{\pi}\ \text{Hz}$. At a certain displacement it has kinetic energy $2\ \text{J}$ and potential energy $1.2\ \text{J}$. The amplitude of oscillation is