HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Physics

The light from the Sun is found to have a maximum intensity near the wavelength of 470 nm. Assuming the surface of the Sun as a black body, the temperature of the Sun is _____________.

[Wien's constant b = 2 .898 x l0^{- 3}mK]

Derive an expression for kinetic energy, when a rigid body is rolling on a horizontal surface without slipping. Hence find kinetic energy for a solid sphere.

A metal ball cools from 64 ^°C to 50 ^°C in 10 minutes and to 42 ^°C in next 10 minutes. The ratio of rates of fall of temperature during the two intervals is _______.

Describe the construction of photoelectric cell.

The susceptibility of magnesium at 300 K is 2.4 x 10^-5. At what temperature will the susceptibility increase to 3.6 x 10^-5?

A network of four capacitors of 6 μF each is connected to a 240 V supply. Determine the charge on each capacitor.

A solid sphere of mass 1 kg rolls on a table with linear speed 2 m/s, find its total kinetic energy.

If a rigid body of radius ‘R’ starts from rest and rolls down an inclined plane of inclination
‘θ’ then linear acceleration of body rolling down the plane is _______.

1000 tiny mercury droplets coalesce to form a bigger drop. In this process, temperature of the drop _______ .

(A) increases

(B) may increase or decrease

(C) decreases

(D) does not change

The difference in tensions in the string at lowest and highest points in the path of the particle of mass 'm' performing vertical circular motion is:....

a) 2 mg

b) 4 mg

c) 6 mg

d) 8 mg

The S.I. unit of compressibility is __________.

A stone of mass 2 kg is whirled in a horizontal circle attached at the end of 1.5m long string. If the string makes an angle of 30° with vertical, compute its period. (g = 9.8 m/s²)

A body cools from 62°C to 54°C in 10 minutes and to 48°C in the next 10 minutes. Find the temperature of the surroundings.

The susceptibility of magnesium at 300K is 1.2 x 10^-5. At what temperature will the susceptibility increase to 1.8 X 10^-5?

A planet is revolving around a star in a circular orbit of radius R with a period T. If the
gravitational force between the planet and the star is proportional to `R^(-3/2)` then

A) `T^2 prop R^(5/2)`

B) `T^2 prop R^((-7)/2)`

C) `T^2 prop R^(3/2)`

D) `T^2 prop R^4`

The substance which allows heat radiations to pass through is _______.

(A) iron

(B) water vapour

(C) wood

(D) dry air

Explain the working of transistor as a switch.

A particle of mass m performs the vertical motion in a circle of radius r. Its potential energy at the highest point is _______. (g is acceleration due to gravity)

The kinetic energy per molecule of a gs at temperature T is ________.

(a) `(3/2)RT`

(b) `(3/2)K_BT`

(c) `(2/3) RT`

(d) `(3/2)("RT"/M)`

A body cools from 80° C to 70° C in 5 minutes and to 62° C in the next 5 minutes. Calculate the temperature of the surroundings.