MAH-MHT CET (PCM/PCB) entrance exam Question Bank Solutions for Physics

When photons of energy hv fall on a metal plate of work function 'W₀', photoelectrons of maximum kinetic energy 'K' are ejected. If the frequency of the radiation is doubled, the maximum kinetic energy of the ejected photoelectrons will be ______.

The average K.E. of hydrogen molecules at 27° C is E. The average K.E. at 627° C is ____________.

A ring of mass m and radius r rotates about an axis passing through its centre and perpendicular to its plane with angular velocity `omega`. Its kinetic energy is ______.

The radius of circle, the period of revolution, initial position, and sense of revolution are indicated in the figure.

y-projection of the radius vector of rotating particle P is:

An iron plate has a circular hole of a diameter 11 cm. Find the diameter of the hole when the plate is uniformly heated from 10° C to 90° C.`[alpha = 12 xx 10^-6//°"C"]`

A metre scale made of a metal reads accurately at 25 °C. Suppose in an experiment an accuracy of 0.12 mm in 1 m is required, the range of temperature in which the experiment can be performed with this metre scale is ______.(coefficient of linear expansion of the metal is `20 xx 10^-6 / (°"C")`

A metal sphere 10.01 cm in diameter is placed on a brass ring of internal diameter 10 cm and at the same temperature of 12° C. The temperature up to which they should be heated together so that the metal sphere just passes through the ring is `[alpha_"metal"= 12 xx 10^-6//°"C" and alpha_"brass" =18 xx 10^-6//°"C"]` ____________.

The unit of intensity of polarization is ____________.

A parallel beam of light is incident normally on a perfectly absorbing surface. If the force exerted by the light beam on the surface is 2 x 10^-7 N in 10 nanoseconds, the energy of photons hitting the surface is ____________.

The average translational kinetic energy of a molecule in a gas becomes equal to 0.49 eV at a temperature about (Boltzmann constant = 1.38 x 10^-23 JK^-1) ____________.

The number of photons falling per second on a completely darkened plate to produce a force of 6.62 x 10^-5 N is 'n'. If the wavelength of the light falling is 5 x 10^-7 m, then n = ____________ x 10²². (h = 6.62 x 10^-34 J-s)

For the weight of body of mass 5 kg to be zero on equator of the earth, angular velocity of the earth must be (The radius of earth = 6400 km, acceleration due to gravity = 10 m/s²).

A metal rod is heated to t°C. A metal rod has length, area of cross-section, Young's modulus and coefficient of linear expansion as 'L', 'A', 'Y' and 'a' respectively. When the rod is heated, the work performed is ______.

A metal rod of Young's moduls 'Y' and coefficient of linear expansion 'a' has its temeprature raised by 'Δ θ'. The linear stress to prevent the expansion of rod is ______.
(L and l is original length of rod and expansion respectively)

The equation of a plane progressive wave is y = 0.09sin8 `pi` `["t" - "x"/20]`.When it is reflected at a rigid support, its amplitude becomes `2/3`rd of its 3 previous value. The equation of the reflected wave is ______.

Average kinetic energy of H₂ molecule at 300K is 'E'. At the same temperature, average kinetic energy of O₂ molecule will be ______.

The force of gravitation between two bodies of mass 1 kg each separated by a distance of 1 m in vacuum is ____________.

The polarizing angle for a transparent medium is 'θ' and 'V' is the speed of light in that medium, then relation between 'θ' and 'V' is (c = velocity of light).

Choose the CORRECT statement from the following.

Brewster's angle for a transparent medium is ______.

When a beam of unpolarised monochromatic light is incident on a plane glass plate at a polarizing angle, then which one of the following statements is correct?