Practice MCQ Questions and answers on Physics-GK

Gamma rays can cause Gene mutation.

Green house effect is the heating up of the Earth's atmosphere which is due to infrared rays.

Visible light has a higher frequency than radio waves.

Infrared radiation has the longest wavelength.

Infrared is used in night vision equipment when there is insufficient visible light to see. Night vision devices operate through a process involving the conversion of ambient light photons into electrons which are then amplified by a chemical and electrical process and then converted back into visible light.

The inside of a car with its windows closed is hotter than outside due to green house effect as the glass in the windows absorb infrared radiations of the sun but do not allow them to escape or reflect back, thus increasing the temperature of the car on the inside.

Radar, which stands for radio detection and ranging, is a system that uses reflected radio waves to detect objects and measure their distance and speed. For example, police use radar to calculate the speed of cars.

The device used for measuring the wavelength of X-rays is Bragg Spectrometer.

The correct relationship among these wavelengths is LUV < lVIS < lIR.

Transition metal ions have an incomplete set of 3d electrons. Changes in the energy of these electrons correspond to the energy of visible light. The absorption of visible light by these ions lend colour to gems.