Measurement Basics: 20 MCQs with answers

Mass

Mass is one of the seven fundamental quantities; speed, force, and area are derived from fundamental quantities.

Candela

The candela (cd) is the SI base unit for luminous intensity. Lumen and lux are derived units for luminous flux and illuminance.

Newton

Newton is derived from base units (kg·m/s²). Kilogram, second, and ampere are base units.

Mole

The mole (mol) is the SI base unit for amount of substance.

Velocity

Velocity is a derived quantity (length/time). Time, temperature, and electric current are fundamental.

Kelvin

The kelvin (K) is the SI base unit for thermodynamic temperature.

Ampere

The ampere (A) is the SI base unit for electric current.

[M⁰ L T⁻¹]

Velocity = displacement/time, so dimensions are [L]/[T] = [M⁰ L T⁻¹].

Luminous intensity

Luminous intensity is one of the seven fundamental quantities. Area, density, and momentum are derived.

True

The kilogram (kg) is indeed the SI base unit for mass.

False

Velocity has both magnitude and direction, so it is a vector quantity, not scalar.

[M L T⁻²]

Force = mass × acceleration, so dimensions are [M][L T⁻²] = [M L T⁻²].

Mass

Mass has only magnitude, no direction. Velocity, force, and acceleration are vectors.

[M L² T⁻²]

Energy (work) = force × distance, so dimensions are [M L T⁻²] × [L] = [M L² T⁻²].

Displacement

Displacement has both magnitude and direction, making it a vector. Speed, distance, and time are scalars.

Radian

The radian (rad) is the SI unit for plane angle. Steradian is for solid angle.

Time and electric current

Time and electric current are both fundamental quantities. Speed, volume, force, and acceleration are derived.

Steradian

The steradian (sr) is the SI unit for solid angle.

Liter

Liter is a non-SI unit for volume. Meter, kilogram, and second are base units.

[M L⁻¹ T⁻²]

Pressure = Force/Area = [M L T⁻²] / [L²] = [M L⁻¹ T⁻²].