NAT Physics MCQs

Percentage uncertainty is absolute uncertainty divided by measured value times 100.
0.2/10.0×100 = 2%.

The kilogram is the SI base unit of mass.
The gram is one-thousandth of a kilogram.

The second is the SI base unit of time.
Minutes and hours are accepted non-SI units derived from it.

A scalar has magnitude only.
Speed has no associated direction.

A vector has both magnitude and direction.
Acceleration describes the rate and direction of velocity change.

Both sides of a valid physical equation must have the same dimensions.
Dimensional analysis can reveal inconsistent formulas.

The newton is derived from base units as kg·m/s².
Metre, kilogram, and second are base units.

Precision describes repeatability.
Measurements can be precise without being accurate.

Accuracy describes agreement with the true or accepted value.
Systematic error can reduce accuracy.

Systematic errors often arise from calibration or method bias.
Repeated measurements do not automatically remove them.

Random errors cause scatter around a central value.
Repeated measurements and averaging can reduce their effect.

Leading zeros are not significant, but trailing zeros after a decimal are.
Thus 4, 5, and the final zero are significant.