List of top Physics Questions asked in MHT CET

A rectifier is used to
A metal wire of length $2500\ \text{m}$ is kept in east-west direction, at a height of $10\ \text{m}$ from the ground. If it falls freely on the ground then the current induced in the wire is (Resistance of wire $= 25\sqrt{2}\ \Omega, g = 10\ \text{m/s}^2$ and Earth's horizontal component of magnetic field $B_H = 2 \times 10^{-5}\ \text{T}$)
The surface energy of a liquid drop is 'U'. It splits up into 512 equal droplets. The surface energy becomes
An air column in a pipe, which is closed at one end will be in resonance with a vibrating tuning fork of frequency 264 Hz for various lengths. Which one of the following lengths is not possible? (V = 330 m/s)
A particle is suspended from a vertical spring which is executing S.H.M. of frequency $5\ \text{Hz}$. The spring is unstretched at the highest point of oscillation. Maximum speed of the particle is ($g = 10\ \text{m/s}^2$)
Photoelectrons are emitted when photons of energy $4.2\ \text{eV}$ are incident on a photosensitive metallic sphere of radius $10\ \text{cm}$ and work function $2.4\ \text{eV}$. The number of photoelectrons emitted before the emission is stopped is
[$\frac{1}{4\pi\epsilon_0} = 9 \times 10^9\ \text{SI unit};\ e = 1.6 \times 10^{-19}\ \text{C}$]
In an ideal step down transformer, out of the following quantities, which quantity increases in the secondary coil?
A parallel plate air capacitor is charged upto $100\ \text{V}$. A plate $2\ \text{mm}$ thick is inserted between the plates. Then to maintain the same potential difference, the distance between the plates is increased by $1.6\ \text{mm}$. The dielectric constant of the thick plate is
Two wires carrying currents $5\ \text{A}$ and $2\ \text{A}$ are enclosed in a circular loop as shown in the figure. Another wire carrying a current of $3\ \text{A}$ is situated outside the loop. The value of $\oint \vec{B} \cdot d\vec{l}$ around the loop is ($\mu_0 = $ permeability of free space, $d\vec{l}$ is the length of the element on the Amperion loop)
A uniformly charged semicircular arc of radius $r$ has linear charge density $\lambda$. What is the electric field at its centre? ($\epsilon_0 =$ permittivity of free space)
The P.E. 'U' of a moving particle of mass 'm' varies with 'x'-axis as shown in figure. The deBroglie wavelength of the particle in the regions $0 \le x \le 1$ and $x > 1$ are $\lambda_1$ and $\lambda_2$ respectively. If the total energy of the particle is 'nE', then the ratio $\lambda_1 / \lambda_2$ is
The ratio of radii of gyration of a circular ring and circular disc of the same mass and radius, about an axis passing through their centres and perpendicular to their planes is
An inductive coil has a resistance of $100\ \Omega$. When an a.c. signal of frequency $1000\ \text{Hz}$ is applied to the coil the voltage leads the current by $45^\circ$. The inductance of the coil is ($\tan 45^\circ = 1$)
In Young's double slit experiment, with a source of light having wavelength $6300\ \text{\AA}$, the first maxima will occur when the
A sample of radioactive element contains $8 \times 10^{16}$ active nuclei. The half-life of the element is 15 days. The number of nuclei decayed after 60 days is
What should be the radius of water drop so that excess pressure inside it is $72\ \text{Nm}^{-2}$? (The surface tension of water $7.2 \times 10^{-2}\ \text{Nm}^{-1}$)
Two consecutive harmonics of an air column in a pipe closed at one end are of frequencies 150 Hz and 250 Hz. The fundamental frequency of an air column is
A body of density $\rho$ is dropped from (at rest) height $h$ into a lake of density $\delta$ ($\delta > \rho$). The maximum depth to which the body sinks before returning to float on the surface is [Neglect all dissipative forces]
Two masses $m_a$ and $m_b$ moving with velocities $v_a$ and $v_b$ in opposite directions collide elastically. After the collision $m_a$ and $m_b$ move with velocities $v_b$ and $v_a$ respectively, then the ratio $m_a : m_b$ is
A monoatomic gas is suddenly compressed to (1/8)th of its initial volume adiabatically. The ratio of the final pressure to the initial pressure is
Which one of the following statements is true?
A particle executes S.H.M. of period $\frac{2\pi}{\sqrt{3}}$ second along a straight line $4\ \text{cm}$ long. The maximum velocity of the particle is
A conducting rod of length $1\ \text{m}$ has area of cross-section $10^{-3}\ \text{m}^2$. One end is immersed in boiling water ($100^\circ\text{C}$) and the other end in ice ($0^\circ\text{C}$). If coefficient of thermal conductivity of copper is $92\ \text{cal}/\text{m-s-}^\circ\text{C}$ and latent heat of ice is $8 \times 10^4\ \text{cal}/\text{kg}$, then the amount of ice which will melt in one minute is
In a single slit diffraction pattern, the distance between the first minimum on the left and the first minimum on the right is $5\ \text{mm}$. The screen on which the diffraction pattern is displayed is at a distance of $80\ \text{cm}$ from the slit. The wavelength is $6000\ \text{\AA}$. The slit width is about
In the case of insulators, a band gap and conduction band is respectively