Physics Questions

The watt-hour (WH) is a unit of energy equivalent to one watt (1 W) of power expended for one hour (1 h) of time.

1 WH = 3600 joules.

Infrared radiation, what we experience as heat when we hold our hand near a warm object, is somewhat longer wavelengths than visible light. Visible light is simply electromagnetic radiation in a range of wavelengths that our eyes are sensitive to. Visible wavelengths range from 0.0007 milimeters for red light, through orange, yellow, green, and blue, to 0.0004 milimeters for violet light. Ultraviolet is shorter wavelengths than violet.

Longer the wavelength,lower the energy

Glass is made from heating of sand. To melt sand to make glass, the temperature needed is above 1800 deg celcius.

A rainbow is a natural spectrum appearing in the sky after a rain shower. It is caused by dispersion of sunlight by tiny water droplets, present in the atmosphere. A rainbow is always formed in a direction opposite to that of the Sun. The water droplets act like small prisms. They refract and disperse the incident sunlight, then reflect it internally, and finally refract it again when it comes out of the raindrops.

Electric power is the rate per unit time, at which electrical energy is transferred by an electric circuit. The power of electricity is measured in watts and kilo watts.

1 Watt is the unit of electrical power equal to one ampere under the pressure of one volt.