Pakistan MCQs

Corrosion involves chemical or electrochemical reactions.
Rusting is a common example involving iron.

Neutrons are electrically neutral.
They are found in atomic nuclei with protons.

Acids donate protons in chemical reactions.
In water, they increase hydrogen-ion concentration.

The proton number is the atomic number.
Changing the proton number creates a different element.

Bases accept protons according to Brønsted-Lowry theory.
Many aqueous bases produce hydroxide ions.

A fuse melts when excessive current heats it.
This interrupts the circuit and helps prevent fire or damage.

Parallel branches have the same potential difference.
Switching off one appliance does not stop current in the others.

An electric motor uses magnetic forces on current-carrying conductors.
It converts electrical energy into motion.

A generator uses electromagnetic induction.
Mechanical motion produces electrical energy.

Lightning tends to strike exposed high points and conductors.
Safer shelter is inside a substantial building or closed vehicle.

Bats emit high-frequency sound pulses and detect returning echoes.
This helps them navigate and locate prey.

Electric current measures charge passing a point per unit time.
Its SI unit is the ampere.