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

Which of the following phenomenon proves that light is a transverse wave?

What is Brewster’s law? Derive the formula for Brewster’s angle.

Calculate the binding energy of an alpha particle given its mass to be 4.00151 u.

An electron in hydrogen atom stays in its second orbit for 10⁻⁸ s. How many revolutions will it make around the nucleus at that time?

In a periodic table the average atomic mass of magnesium is given as 24.312 u. The average value is based on their relative natural abundance on earth. The three isotopes and their masses are\[\ce{_12^24Mg}\](23.98504 u), \[\ce{_12^25Mg}\] (24.98584 u), and \[\ce{_12^26Mg}\] (25.98259 u). The natural abundance of \[\ce{_12^24Mg}\] is 78.99% by mass. Calculate the abundances of other two isotopes.

State two applications of Pascal's law.

When unpolarized light is passed through a polarizer, its intensity ______.

Give an example of some familiar process in which heat is added to an object, without changing its temperature.

Answer in brief.

Why should a Carnot cycle have two isothermal two adiabatic processes?

An ideal gas is taken through an isothermal process. If it does 2000 J of work on its environment, how much heat is added to it?

Unpolarized light with intensity I₀ is incident on two polaroids. The axis of the first polaroid makes on the angle of 50° with the vertical, and the axis of the second polaroid is horizontal. What is the intensity of the light after it has passed through the second polaroid?

A sound wave in a certain fluid medium is reflected at an obstacle to form a standing wave. The distance between two successive nodes is 3.75 cm. If the velocity of sound is 1500 m/s, find the frequency.

Two sound waves travel at a speed of 330 m/s. If their frequencies are also identical and are equal to 540 Hz, what will be the phase difference between the waves at points 3.5 m from one source and 3 m from the other if the sources are in phase?

A pipe closed at one end can produce overtones at frequencies 640 Hz, 896 Hz, and 1152 Hz. Calculate the fundamental frequency.

Find the fundamental, first overtone, and second overtone frequencies of a pipe, open at both the ends, of length 25 cm if the speed of sound in air is 330 m/s.

A pipe open at both the ends has a fundamental frequency of 600 Hz. The first overtone of a pipe closed at one end has the same frequency as the first overtone of the open pipe. How long are the two pipes?

(Given: v = 330 m/s)

A string 1m long is fixed at one end. The other end is moved up and down with frequency of 15 Hz. Due to this, a stationary wave with four complete loops gets produced on the string. Find the speed of the progressive wave which produces the stationary wave.
[Hint: Remember that the moving end is an antinode.]

A violin string vibrates with fundamental frequency of 440Hz. What are the frequencies of the first and second overtones?

A set of 8 tuning forks is arranged in a series of increasing order of frequencies. Each fork gives 4 beats per second with the next one and the frequency of last fork is twice that of the first. Calculate the frequencies of the first and the last fork.

A device Y is connected across an AC source of emf e = e₀ sin ωt. The current through Y is given as i = i₀ sin (ωt + π/2).

1. Identify the device Y and write the expression for its reactance.
2. Draw graphs showing a variation of emf and current with time over one cycle of AC for Y.
3. How does the reactance of the device Y vary with the frequency of the AC? Show graphically.
4. Draw the phasor diagram for device Y.