CSS General Knowledge MCQs

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

Metals transfer heat efficiently from the flame to food.
This makes cooking faster and more even.

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

Soft porous materials absorb part of the sound energy.
This reduces excessive reverberation and improves clarity.

Both spoons may have the same temperature.
Metal removes heat from the skin more quickly, creating a colder sensation.

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

Heating usually increases particle motion and separation.
This commonly causes thermal expansion.

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

Metal structures expand in hot weather.
Gaps prevent buckling and structural damage.

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

Melting occurs when a solid gains enough energy to become liquid.
It happens at the melting point under fixed pressure.

Spectacle lenses change the convergence of light entering the eye.
They help focus images correctly on the retina.