Explanation

The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium.

Explanation

Explanation

Ophthalmologist means a specialist in the branch of medicine concerned with the study and treatment of disorders and diseases of the eye.

Ophthalmologist means ماہر امراض چشم

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Explanation

Rocket works on the principle of conservation of linear momentum.

conservation of linear momentum and third law of motion

The hot gases acquire momentum in the backward direction

& the rocket acquires an equal amount of momentum in the forward direction.

Explanation

Vexillology is the study of flags.

 Vexillology comes from the Latin word vexilla "little sail" for flag.

Vexillology means جھنڈوں کا مطالعہ

Explanation

Electronics is the branch of science that studies the flow and control of electrons, especially in circuits.

It uses active devices (like transistors and diodes) to control electron flow through amplification and rectification.

Explanation

• Gamma rays have the highest energy among the options.
• They are electromagnetic waves with extremely high frequency and short wavelength.
• It gives them more energy compared to Alpha, Beta, and X-rays.

Explanation

The Pyrometer is used for measuring very high temperatures.

Pyrometers can measure temperatures without direct contact.

This making them ideal for extreme conditions.

Explanation

3% of Earth's water is fresh water.

2.5% of that fresh water is unavailable because it is:

• Locked in glaciers and polar ice caps
• Present in the atmosphere and soil
• Too deep underground to extract affordably

Only 0.5% of Earth's water is available as usable fresh water for human use.

Explanation

The SI unit of pressure is Pascal (represented as Pa) 

in SI base units, one kilogram per meter per second squared (N/m2 or kg m-1s-2)

Definition of Pressure: Pressure can be defined as the force acting per unit area.

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The SI unit of energy/work is the joule (J)