Practice MCQ Questions and answers on Physics-GK

Angstroms (A°) to nanometers (nm) is:
1 A° = 0.1 nm
So, to convert 70 A° to nanometers:
70 A° × 0.1 nm/A° = 7 nm
Therefore, the correct answer is Option A: 7 nm.

Lux, unit of illumination (see luminous intensity) in the International System of Units (SI). One lux (Latin for “light”) is the amount of illumination provided when one lumen is evenly distributed over an area of one square metre.

An atomic clock is a clock device that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element. Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.

Parsec is the unit of Astronomical Distance.

Light year is the unit of Astronomical distance.

The lux (symbol: lx) is the SI unit of illuminance and luminous emittance. It is used in photometry as a measure of the intensity of light, with wavelengths weighted according to the luminosity function, a standardized model of human brightness perception.

We measure sound intensity (also referred to as sound power or sound pressure) in units called decibels. Decibels (dB) are named in honor of Alexander Graham Bell, the inventor of both the telephone and the audiometer.

Light year - Time is an incorrect pair.

Radian is used to measure angle.

Joule per kelvin is the unit of the physical quantity Entropy.