FPSC MCQs

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.

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

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.

Conduction transfers thermal energy through particle interactions.
It is especially important in solids.

Convection occurs when warmer fluid moves and cooler fluid replaces it.
It happens in liquids and gases.

Thermal radiation travels as electromagnetic waves.
It does not require a material medium.

Space between the Sun and Earth is nearly a vacuum.
Solar energy reaches Earth as electromagnetic radiation.