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

Explain the formation of energy band diagram in case of conductor and semiconductor.

State the conditions to get steady interference pattern.

In a hydrogen atom, an electron carrying charge 'e' revolves in an orbit of radius 'r' with speed 'v'. Obtain an expression for the magnitude of magnetic moment of a revolving electron.

A solenoid of length 1.5 m and 4 cm in diameter possesses 10 turns per metre. A current of 5 A is flowing through it. The magnetic induction at a point inside the solenoid along the axis is ............................. .

(μ₀ = 4π × 10^-7 Wb/Am)

1. π  × 10^-5 T
2. 2π × 10^-5 T
3. 3π × 10^-5 T
4. 4π × 10^-5 T

A solenoid of length 1.5 m and 4 cm in diameter possesses 10 turns per metre. A current of 5 A is flowing through it. The magnetic induction at a point inside the solenoid along the axis is ............................. .

(μ₀ = 4π × 10^-7 Wb/Am)

1. π  × 10^-5 T
2. 2π × 10^-5 T
3. 3π × 10^-5 T
4. 4π × 10^-5 T

The photoelectric work function for a metal is 4.2 eV. If  the stopping potential is 3V, find the threshold wavelength and maximum kinetic energy of emitted electrons. 

(Velocity of light in air = 3 x 10⁸m/s,
Planck's constant = 6·63 x10^-34 J -s,
Charg.e ori electron = 1·6 x 10 ^-19 C)

A copper metal cube has each side of length 1 m. The bottom edge of the cube is fixed and tangential force 4.2x10⁸ N is applied to a top surface. Calculate the lateral displacement of the top surface if modulus of rigidity of copper is 14x10¹⁰ N/m².

A metal rod `1/sqrtpi `m long rotates about one of its ends perpendicular to a plane whose magnetic induction is 4 x 10^-3 T. Calculate the number of revolutions made by the rod per second if the e.m.f. induced between the ends of the rod is 16 mV.

A metal rod `1/sqrtpi `m long rotates about one of its ends perpendicular to a plane whose magnetic induction is 4 x 10^-3 T. Calculate the number of revolutions made by the rod per second if the e.m.f. induced between the ends of the rod is 16 mV.

State Ampere’s circuital law.

Calculate the radius of second Bohr orbit in hydrogen atom from the given data.

Mass of electron = 9.1 x 10^-31kg

Charge on the electron = 1.6 x 10^-19 C

Planck’s constant = 6.63 x 10^-34 J-s.

Permittivity of free space = 8.85 x 10^-12 C²/Nm²

State Ampere’s circuital law.

Choose the correct option.

If the pressure of an ideal gas decreases by 10% isothermally, then its volume will ______.

If the charge on the condenser of 10°F is doubled, then the energy stored in it becomes __________

Distinguish between the phenomenon of interference and diffraction of light.

The magnetic flux through a loop is varying according to a relation `phi = 6t^2 + 7t + 1` where `phi` is in milliweber and t is in second. What is the e.m.f. induced in the loop at t = 2 second?

The magnetic flux through a loop is varying according to a relation `phi = 6t^2 + 7t + 1` where `phi` is in milliweber and t is in second. What is the e.m.f. induced in the loop at t = 2 second?

Find the frequency of revolution of an electron in Bohr’s 2nd orbit; if the radius and speed of electron in that orbit is 2.14 × 10^-10 m and 1.09 × 10⁶ m/s respectively. [π= 3.142]

Draw a neat, labelled energy level diagram for H atom showing the transitions. Explain the series of spectral lines for H atom, whose fixed inner orbit numbers are 3 and 4 respectively.

The work functions for potassium and caesium are 2.25 eV and 2.14 eV respectively. Is the photoelectric effect possible for either of them if the incident wavelength is 5180 Å?

[Given : Planck’s constant = 6.63 x 10^–34 J.s.;
Velocity of light = 3 x 10⁸ m/s; 1 eV = 1.6 x 10^–19 J]