Pakistan MCQs

Boiling water is cooler at high altitude.
The lower cooking temperature slows many cooking processes.

Sound requires particles to transmit vibrations.
A vacuum contains too few particles for sound propagation.

Pressure inside the cooker increases above atmospheric pressure.
Water then boils at a higher temperature and cooks food faster.

Pitch rises as vibration frequency increases.
Low frequencies produce lower-pitched sounds.

Visible light is part of the electromagnetic spectrum.
It can travel through a vacuum.

Greater wave amplitude carries more energy.
It is generally perceived as a louder sound.

Non-luminous objects become visible when illuminated.
Reflected light enters the eyes and forms an image.

Sound waves can reflect from distant surfaces.
If the delay is sufficient, the reflected sound is heard as an echo.

Reflection from a smooth surface obeys equal incidence and reflection angles.
Both angles are measured from the normal.

A plane mirror forms a virtual image behind the mirror.
The image is upright, same-sized, and left-right reversed.

Light changes speed when moving between media.
This speed change usually causes bending, called refraction.

Light from the submerged part changes direction when leaving water.
The brain traces rays backward and sees an apparent displacement.