Units and Measurements — Physics STD 11 Science — Question

A gas is filled in a cylinder fitted with a piston at a definite temperature and pressure. Why the pressure of the gas decreases when the piston is pulled out?

Can a system be heated and its temperature remains constant?

The separation between a node and the next antinode in a vibrating air column is 25cm. If the speed of sound in air is 340m/s, find the frequency of vibration of the air column.

How far above the earth's surface does the value of g becomes 20% of its value on the surface?

A water pipe entering a hose has a dimeter of 2cm and the speed of water is 0.1ms^-1. Eventually, the pipe tapers to a diameter of 1cm. Calculate the speed of water in the tapered portion.

You are riding in a car. The driver suddenly applies the brakes and you are pushed forward. Who pushed you forward?

Find the maximum potential difference which may be applied across an X-ray tube with tungsten target without emitting any characteristic K or L X-ray. The energy levels of the tungsten atom with an electron knocked out are as follows.

Cell containing vacancy	K	L	M
Energy in keV	69.5	11.3	2.3

Heat is transferred from inside a refrigerator at 287 K to a room at 310 K ideally, how much heat (in joules) will be given to the room by the expenditure of each joule of electrical energy?