PMS MCQs

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

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

Ice has an open crystal structure that occupies more volume.
Its lower density causes it to float on water.

Freezing expands water into a less dense solid structure.
The resulting ice is buoyant in liquid water.

A raised object has energy because of its position in a gravitational field.
This energy can convert to kinetic energy as it falls.

Kinetic energy is the energy of motion.
It depends on the object's mass and speed.

Inertia causes an object to remain at rest or in uniform motion unless acted on.
Greater mass generally means greater inertia.

The fan's motor converts electrical energy into rotation.
Some energy is also lost as heat and sound.

Their bodies tend to continue moving forward when the bus stops.
This is an example of inertia of motion.

Chemical reactions inside a battery create an electric potential.
The stored chemical energy is converted into electrical energy.

Newton's third law describes paired interaction forces.
Each force is matched by an equal force in the opposite direction.

Solar cells use the photovoltaic effect.
They convert light directly into electrical energy.