SI Units | MCQs

Explanation

The ampere, symbol A, is the SI unit of electric current.

It is defined by considering the fixed  value of the elementary charge e as 1.602 176 634 x 1019,

where the unit C is equal to As and the second is defined by Δν Cs.

Explanation

The SI unit of energy/work is the joule (J)

named for English physicist James Prescott Joule (1818 - 1889).

Joule discovered the relationship between heat and mechanical work, which led to the development of the laws of thermodynamics.

Explanation

• The Candela (cd) is the SI unit of luminous intensity.
• It is defined as the luminous intensity of a monochromatic source that emits light at a frequency of 540 x 10^12 Hz with a luminous efficiency of 683 lm/W.

Explanation

The SI unit of acceleration is meters/second^2 (m/s^2 or ms^-2)

Acceleration (a) is defined as the rate of change of velocity.

Velocity is a vector quantity, and therefore acceleration is also a vector quantity.

Explanation

• The Mole (mol) is the SI unit of amount of substance, representing 6.022 x 10^23 particles.
• It is used to measure the amount of a substance in a sample.