Physics Questions

A seconds pendulum is a pendulum whose period is precisely two seconds i.e, one second for a swing in one direction and one second for the return swing.

Wavelength of a wave can be measured with the distance between two nearest crest and crest or nearest troughs. It is measured as armstrong units.

Electrical discharge machining (EDM), also known as spark machining, spark eroding, burning, die sinking, wire burning or wire erosion, is a manufacturing process whereby a desired shape is obtained by using electrical discharges.

The device which is used to measure air pressure is called as barometer. If the barometer reading is rising, it indicates that the air pressure is increasing and if the reading is falling the air pressure is decreaing.

According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.Therefore, light other than red is mostly scattered away. Most of the red light, which is the least scattered, enters our eyes. Hence, the sun and the sky appear red.