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

State any four applications of beats.

Two wires of the same material and same cross-section are stretched on a sonometer. One wire is loaded with 1 kg and another is loaded with 9 kg. The vibrating length of the first wire is 60 cm and its fundamental frequency of vibration is the same as that of the second wire. Calculate the vibrating length of the other wire. 

A stretched sonometer wire is in unison with a tuning fork. When the length is increased by 4%, the number of beats heard per second is 6. Find the frequency of the fork.

Explain the production of beats and deduce analytically the expression for beats frequency.

Two coherent sources whose intensity ratio is 25:1 produce interference fringes. Calculate the ratio of amplitudes of light waves coming from them.

Why two light sources must be of equal intensity to obtain a well-defined interference pattern?

Draw a neat labelled ray diagram of the Fresnel Biprism experiment showing the region of interference. 

What is interference?

Describe geometry of the Young’s double slit experiment with the help of a ray diagram. What is fringe width? Obtain an expression of it. Write the conditions for constructive as well as destructive interference. 

What are coherent sources of light? 

Explain constructive and destructive interference with the help of a diagram?

The magnetic dipole moment of the current loop is independent of ______  

State the orientation of magnetic dipole with respect to a magnetic field, which possesses maximum magnetic potential energy.

Prove that the frequency of beats is equal to the difference between the frequencies of the two sound notes giving rise to beats.

Define Impedance.

Two tuning forks of frequencies 320 Hz and 340 Hz are sounded together to produce a sound wave. The velocity of sound in air is 326.4 m/s. Calculate the difference in wavelengths of these waves.

In a double-slit experiment, the optical path difference between the waves coming from two coherent sources at a point P on one side of the central bright is 7.5 µm and that at a point Q on the other side of the central bright fringe and 1.8 µm. How many bright and dark fringes are observed between points P and Q if the wavelength of light used is 600 nm?

If beat frequency is 2 Hz, what is the time interval between success waxings?

Draw a neat labelled P - V diagram for a typical heat engine. 

The thermal efficiency of a heat engine is 25%. If in one cycle the heat absorbed from the hot reservoir is 50000 J, what is the heat rejected to the cold reservoir in one cycle?