HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

Obtain an expression for total kinetic energy of a rolling body in the form

`1/2 (MV^2)[1+K^2/R^2]`

The photoelectric work function for a metal surface is 2.3 eV. If the light of wavelength 6800A is incident on the surface of metal, find threshold frequency and incident frequency. Will there be an emission of photoelectrons or not?

[Velocity of light c = 3 x 10⁸ m/s,

Planck’s constant, h = 6.63 * 10^-34 Js ]

The kinetic energy of a rotating body depends upon................

1. distribution of mass only.
2. angular speed only.
3. distribution of mass and angular speed.
4. angular acceleration only.

The dimensions of universal gravitational constant are........................

a. [L¹M⁰T⁰]

b. [L²M¹T⁰]

c. [L^-1M¹T^-2]

d. [L³M^-1T^-2]

Calculate the period of revolution of Jupiter around the Sun. The ratio of the radius of Jupiter’s orbit to that of the Earth’s orbit is 5.

(Period of revolution of the Earth is 1 year)

Electric field intensity in free space at a distance ‘r’ outside the charged conducting sphere of radius ‘R’ in terms of surface charge density ‘ a ’ is............................

(a)`sigma / in_0[R/r]^2`

(b)`in_0/sigma[R/r]^2`

(c)`R/r[sigma/in_0]^2`

(d)`R/sigma[r/in_0]^2`

Electric field intensity in free space at a distance ‘r’ outside the charged conducting sphere of radius ‘R’ in terms of surface charge density ‘ a ’ is............................

(a)`sigma / in_0[R/r]^2`

(b)`in_0/sigma[R/r]^2`

(c)`R/r[sigma/in_0]^2`

(d)`R/sigma[r/in_0]^2`

The magnetic flux through a loop varies according to the relation Φ = 8t² + 6t + C, where ‘C’ is constant, 'Φ' is in milliweber and 't' is in second. What is the magnitude of induced e.m.f. in the loop at t = 2 seconds.

The magnetic flux through a loop varies according to the relation Φ = 8t² + 6t + C, where ‘C’ is constant, 'Φ' is in milliweber and 't' is in second. What is the magnitude of induced e.m.f. in the loop at t = 2 seconds.

An electron is orbiting in 5^th Bohr orbit. Calculate ionisation energy for this atom, if the ground state energy is -13.6 eV.

Obtain an expression for the radius of Bohr orbit for H-atom.

A seconds pendulum is suspended in an elevator moving with constant speed in downward direction. The periodic time (T) of that pendulum is _______.

The periodic time of a linear harmonic oscillator is 2π second, with maximum displacement of 1 cm. If the particle starts from extreme position, find the displacement of the particle after π/3  seconds.

Show that all harmonics are present on a stretched string between two rigid supports.

State Bohr’s third postulate for hydrogen (H2) atom. Derive Bohr’s formula for the wave number. Obtain expressions for longest and shortest wavelength of spectral lines in ultraviolet region for hydrogen atom

The photoelectric current in a photoelectric cell can be reduced to zero by a stopping potential of 1.8 volt. Monochromatic light of wavelength 2200Å is incident on the cathode. Find the maximum kinetic energy of the photoelectrons in joules. [Charge on electron = 1.6 x 10^-19 C]

Draw a neat labelled circuit diagram of experimental arrangement for study of photoelectric effect.

A parallel beam of monochromatic light is incident on a glass slab at an angle of incidence 60^o. Find the ratio of width of the beam in the glass to that in the air if refractive index of glass is 3/2.

The co-efficient of reflection of an opaque body is 0.16. Its co-efficient of emission is ........................................

1. 0.94
2. 0.84
3. 0.74
4. 0.64

Draw neat, labelled diagrams for the modes of vibration of a stretched string in second harmonic and third harmonic.