Explanation

Rainwater is formed through evaporation and condensation, a natural distillation process that leaves most impurities and salts behind.

This process effectively purifies the water, making it the purest form found in nature.

Explanation

A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters.

A nautical mile equals 1.852 km.

It is used in air and sea travel.

It is based on the Earth’s circumference, making it ideal for navigation.

Explanation

The unit of measurement for inductance is the henry (H).

It is the International System of Units (SI) unit.

The henry is named after Joseph Henry, the physicist who independently discovered inductance.

Explanation

• The electrons that have been knocked out of the outermost shell of an atom are free electrons, which are able to move freely and conduct electricity.

Explanation

A magnetometer is specifically designed to measure the strength and direction of a magnetic field.

Flux meter measures magnetic flux.

Galvanometer measures electric current.

Explanation

A real gas can be approximated to an ideal gas at low density.

This is typically achieved under conditions of low pressure and high temperature. 

Explanation

The resolving power of a telescope is its ability to produce separate images of two closely spaced objects, like two distant stars.

It is directly proportional to the diameter (aperture) of the objective lens or mirror.

Explanation

Turning effect of force is called torque

Torque is used to measure coupling while the moment is not.

Both torque and moment have the Newton meter as the SI unit; torque is presented as Nm/revolution while moment is presented as Nm.

Moment is a static force while torque is a movement force.

Explanation

When white light passes through a prism, different wavelengths bend by different amounts.

This dispersion due to refraction splits light into seven colors (VIBGYOR).

Explanation