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

Explain why an astronaut in an orbiting satellite has a feeling of weightlessness.

State the theorem of perpendicular axes about moment of inertia.

Calculate the average molecular kinetic energy :

(a) per kilomole, (b) per kilogram, of oxygen at 27°C.

(R = 8320 J/k mole K, Avogadro's number = 6*03 x 10²⁶ molecules/K mole)

What are the forced vibrations and resonance?

Obtain an expression for potential energy of a particle performing simple harmonic motion. Hence evaluate the potential energy

1. at mean position and
2. at extreme position.

What is a Polaroid?

State an expression for the moment of intertia of a solid uniform disc, rotating about an axis passing through its centre, perpendicular to its plane. Hence derive an expression for the moment of inertia and radius of gyration:

i. about a tangent in the plane of the disc, and

ii. about a tangent perpendicular to the plane of the disc.

A sonometer wire is in unison with a tuning fork of frequency 125 Hz when it is stretched by a weight. When the weight is completely immersed in water, 8 beats are heard per second. Find the specific gravity of the material of the weight.

A rectangular coil of a moving coil galvanometer contains 50 turns each having area 12 cm2 . It is suspended in radial magnetic field 0.025 Wb/m² by a fibre of twist constant 15 x10^-10 Nm/degree. Calculate the sensitivity of the moving coil galvanometer.

With the help of neat diagram, explain how non-polar dielectric material is polarised in external electric field of increasing intensity. Define polarisation in dielectrics.

In a single slit diffraction pattern, the distance between first minima on the right and first minima on the left of central maximum is 4 mm. The screen on which the pattern is displaced, is 2m from the slit and wavelength of light used is 6000Å. Calculate width of the slit and width of the central maximum.

Distinguish between forced vibrations and resonance.

Show that the current flowing through a moving coil galvanometer is directly proportional to the angle of deflection of coil.

Draw a neat labelled diagram showing the plane of vibration and plane of polarisation for polarised light.

Prove the theorem of parallel axes about moment of inertia

Write the underlying principle of a moving coil galvanometer.

State Brewster's law.

Differentiate between free and forced vibrations.

A train blows a whistle of frequency 640 Hz in air. Find the difference in apparent frequencies of the whistle for a stationary observer, when the train moves towards and away from the observer with the speed of 72 Km/hour. [Speed of sound in air = 340 m/s.]

In the diffraction pattern due to a single slit of width 'd' with incident light of wavelength 'λ', at an angle of  diffraction θ. the condition for first minimum is ....

(a)`lambda sin theta =d`

(b) `d costheta =lambda`

(c)`d sintheta=lambda`

(d) `lambda cos theta=d`