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

The dipole moment of a water molecule is 6.3 x 10^-30 c·m. A sample of water contains 10²¹ molecules, whose dipole moments are all oriented in an electric field of strength 2.5 x 10⁵N/C. Calculate the work to be done to rotate the dipoles from their initial orientation θ₁ = 0° to one in which all the dipoles are perpendicular to the field, θ₂ = 90°.

A search coil having 2000 turns with area 1.5 cm² is placed in a magnetic field of 0.60 T. The coil is moved rapidly out of the field in a time of 0.2 s. Calculate the induced emf in the search coil.

Calculate the induced emf between the ends of an axle of a railway carriage 1.75 m long traveling on level ground with a uniform velocity of 50 kmph. The vertical component of Earth's magnetic field (B_v) is 5 × 10^-5 T. 

Determine the maximum angular speed of an electron moving in a stable orbit around the nucleus of the hydrogen atom.

A string of length ℓ fixed at one end carries a mass m at the other. The string makes 2/π revolutions/sec around the vertical axis through the fixed end. The tension in the string is ______.

State and explain the theorem of parallel axes.

Show that the average energy of the molecules of a gas is directly proportional to the absolute temperature of the gas. 

Determine the molecular kinetic energy (i) per mole (ii) per gram (iii) per molecule of nitrogen molecules at 227°C, R = 8.310 J mole^-1 K^-1,No = 6.03 x 10²⁶ moleculesKmole^-1. Molecular weight of nitrogen = 28. 

Two S.H.M.’s have zero phase difference and equal amplitudes A. The resultant amplitude on their composition will be ______ 

A simple pendulum moves from one end to the other in ¼ second. What is its frequency?

What is the amplitude of S.H.M. 

The acceleration due to gravity on the surface of the moon is 1.7 m/s². What is the time period of a simple pendulum on the surface of the moon if its time period on the surface of the earth is 3.5 s? (g on the surface of earth = 9.8 m/s²) 

A particle performing S.H.M. has velocities of 8 cm/s and 6 cm/s at displacements of 3 cm and 4 cm respectively. Calculate the amplitude and period of S.H.M.

A particle performs linear S.H.M. of period 4 seconds and amplitude 4 cm. Find the time taken by it to travel a distance of 1 cm from the positive extreme position.

Obtain an expression for the resultant amplitude of, the composition of two S.H.M.’s having the same period along the same path.  

State law of length.

What are forced vibrations? 

Show that even as well as odd harmonics are present as an overtone in modes of vibration of the string. 

A dipole is placed in a uniform electric field, its potential energy will be minimum when the angle between its axis and field is ______ 

A molecule with a dipole moment p is placed in an electric field of strength E. Initially the dipole is aligned parallel to the field. If the dipole is to be rotated to be anti-parallel to the field, find the work required to be done by an external agent.