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

How the linear velocity 'v' of an electron in the Bohr orbit is related to its quantum number 'n'?

The radius of electron's second stationary orbit in Bohr's atom is R. The radius of the third orbit will be ______

The ratio of speed of an electron in the ground state in the Bohr's first orbit of hydrogen atom to velocity of light (c) is ____________.

(h = Planck's constant, ε₀ = permittivity of free space, e = charge on electron)

Light entering an air glass (µ = 1.5) boundary is partly reflected and partly refracted. If the incident and reflected rays are at right angles to each other, the angle of refraction r is given by ____________.

Using Bohr's model, the orbital period of electron in hydrogen atom in nth orbit is (ε₀ = permittivity of free space, h = Planck's constant, m = mass of electron and e = electronic charge)

The Brewster's angle for the glass-air interface is (54.74)°. If a ray of light passing from air to glass strickes at an angle of incidence 45°, then the angle of refraction is ______.
`[tan (54.74)° = sqrt2, sin 45 = 1/sqrt2]`

Bohr model is applied to a particle of mass 'm' and charge 'q' is moving in a plane under the influence of a transverse magnetic field 'B. The energy of the charged particle in the nth level will be (h = Planck's constant).

The wavelength of the first line in Balmer series in the hydrogen spectrum is 'λ'. What is the wavelength of the second line in the same series?

A clock pendulum having coefficient of linear expansion. α = 9 × 10^-7/°C^-1 has a period of 0.5 s at 20°C. If the clock is used in a climate, where the temperature is 30°C, how much time does the clock lose in each oscillation? (g = constant)

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 ____________.

With the increase in principal quantum number, the energy difference between the two successive energy levels ____________.

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 ratio of the velocity of the electron in the first orbit to that in the second orbit is ____________.

Which of the following statements about the Bohr model of the hydrogen atom is FALSE?

When the electron in hydrogen atom jumps from fourth Bohr orbit to second Bohr orbit, one gets the ______.

For a certain atom when the system moves from 2E level to E, a photon of wavelength `lambda` is emitted. The wavelength of photon produced during its transition from `(4"E")/3` level to E is ____________.

How many moles of electrons are required for reduction of 9 moles of Cr³⁺ to Cr?

If the ionisation potential of helium atom is 24.6 volt, the energy required to ionise it will be ____________.

Taking the Bohr radius as a₀= 53 pm, the radius of Li⁺⁺ ion in its ground state, on the basis of Bohr's model, will be about ______.