PART - 2 CH - 13 Oscillations — Physics STD 11 Science — Question

During summers in India, one of the common practice to keep cool is to make ice balls of crushed ice, dip it in flavoured sugar syrup and sip it. For this a stick is inserted into crushed ice and is squeezed in the palm to make it into the ball. Equivalently in winter, in those areas where it snows, people make snow balls and throw around. Explain the formation of ball out of crushed ice or snow in the light of P–T diagram of water.

Consider the situation shown in figure. The wire PQ has mass m, resistance r and can slide on the smooth, horizontal parallel rails separated by a distance l. The resistance of the rails is negligible. A uniform magnetic field B exists in the rectangular region and a resistance R connects the rails outside the field region. At t = 0, the wire PQ is pushed towards right with a speed v₀. Find

1. The current in the loop at an instant when the speed of the wire PQ is v.
2. The acceleration of the wire at this instant.
3. The velocity vas a functions of x.
4. The maximum distance the wire will move.

A body weighs 63N on the surface of the earth. What is the gravitational force on it due to the earth at a height equal to half the radius of the earth?

Define molar specific heat capacities at constant volume and pressure. Considering thermodynamical process in a cylinder with parameters P, V and T, derive the Mayer's relation.

Explain Doppler effect in sound. Obtain an expression for apparent frequency of sound when source and listener are approaching each other.

A convex lens has a focal length of 10cm. Find the location and nature of the image if a point object is placed on the principal axis at a distance of:

1. 9.8cm
2. 10.2cm from the lens.

Figure. shows a large closed cylindrical tank containing water. Initially the air trapped above the water surface has a height h₀ and pressure 2p₀ where p₀ is the atmospheric pressure. There is a hole in the wall of the tank at a depth h₁ below the top from which water comes out. A long vertical tube is connected as shown.

1. Find the height h₂ of the water in the long tube above the top initially.
2. Find the speed with which water comes out of the hole.
3. Find the height of the water in the long tube above the top when the water stops coming out of the hole.

A mica strip and a polysterene strip are fitted on the two slits of a double slit apparatus. The thickness of the strips is 0.50mm and the separation between the slits is 0.12cm. The refractive index of mica and polysterene are 1.58 and 1.55 respectively for the light of wavelength 590nm which is used in the experiment. The interference is observed on a screen a distance one meter away.

1. What would be the fringe-width?
2. At what distance from the centre will the first maximum be located?