Measurement & Motion: 26 MCQs with answers

Metre

The metre is the base SI unit of length. Centimetre, kilometre, and millimetre are other metric units but not the SI base unit.

Metre per second

Speed is distance divided by time, so its unit is metre per second (m/s).

A reference point

Motion is defined relative to a reference point. Without a reference point, motion cannot be described.

A point on a rotating fan blade

A point on a rotating fan blade moves in a circle around the centre, so it is circular motion.

Pascal

Pascal is the SI unit of pressure, not length. Angstrom, light year, and parsec are units of length.

Rectilinear motion

A train moving on a straight track covers a straight line path, so it is rectilinear motion.

True

The second is the SI base unit of time.

False

A ceiling fan rotates about a fixed axis, so it exhibits circular motion, not rectilinear motion.

Meter

The basic unit of length in the SI system is the meter.

Ruler

A ruler is a common tool used for measuring length.

Remains constant

An object at rest does not change its position relative to a reference point.

Displacement

Displacement refers to the distance traveled in a specific direction.

Velocity

Velocity is defined as the rate of change of position of an object.

Rectilinear motion

Rectilinear motion refers to motion that occurs along a straight line.

Covers equal distances in equal intervals of time

Uniform motion means covering equal distances in equal intervals of time.

Meters per second

Speed is commonly measured in meters per second (m/s).

To measure length

A measuring tape is specifically designed to measure length.

Aligned with the starting point of the object

The zero mark should be aligned with the starting point of the object for accurate measurement.

Directly above the point of measurement

To avoid parallax error, the eye must be directly above the point where the measurement is taken.

A thread and a metre scale

A thread is placed along the curved line, then straightened and measured with a scale. This is the standard method.

Periodic

A pendulum repeats its motion at regular intervals, so it is periodic motion.

1 mm

A standard metre scale has markings up to 1 mm, so its least count is 1 mm (0.1 cm).

Uniform

Uniform motion means equal distances in equal time intervals. Non-uniform motion covers unequal distances.

Start from another full mark and subtract the initial reading

If the zero mark is damaged, start from a full mark (e.g., 1 cm) and subtract that initial reading from the final reading to get the correct length.

One complete oscillation

The time period is the time for one complete to-and-fro motion (one oscillation).

Place one end of the object at the zero mark and read the other end

The object should be placed with one end at the zero mark, and the reading at the other end gives the length.