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

Which property of soft iron makes it useful for preparing electromagnet?

What should be retentivity and coercivity of permanent magnet?

Answer in brief.

Explain one application of electromagnet.

Compare resistance and reactance.

Answer in brief:

What are harmonics and overtones?

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.