PPSC MCQs

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

Archimedes' principle relates buoyant force to displaced fluid.
The upward force equals the weight of the displaced fluid.

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

A ship contains large air-filled spaces.
Its total mass spread over its volume gives an average density below water.

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

Density compares mass with the space occupied.
It is calculated as mass divided by volume.

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

Pressure is force distributed over an area.
The same force produces greater pressure on a smaller area.

A sharp edge concentrates force over a small area.
This creates greater pressure and makes cutting easier.

Pressure is measured in pascals.
One pascal equals one newton per square metre.

Pascal's law states that pressure applied to a confined fluid is transmitted equally.
This allows force multiplication in hydraulic brakes.

Gravity continuously accelerates the ball downward.
After slowing to a stop, it begins falling.