FPSC MCQs

Violet light has the shortest wavelength among visible colors.
It also has the highest visible-light frequency.

Wind carries away water vapor near the fabric.
This maintains a concentration difference and speeds evaporation.

Rayleigh scattering is stronger for shorter visible wavelengths.
Scattered blue light reaches observers from many directions.

At boiling, vapor bubbles form throughout the liquid.
It occurs when vapor pressure matches external pressure.

Sunlight travels through more atmosphere near the horizon.
Much of the shorter-wavelength light is scattered away.

Atmospheric pressure decreases with altitude.
Lower pressure allows water to boil at a lower temperature.

Sound begins with vibrating matter.
It travels through a medium as pressure variations.

Boiling water is cooler at high altitude.
The lower cooking temperature slows many cooking processes.

Sound requires particles to transmit vibrations.
A vacuum contains too few particles for sound propagation.

Pressure inside the cooker increases above atmospheric pressure.
Water then boils at a higher temperature and cooks food faster.

Pitch rises as vibration frequency increases.
Low frequencies produce lower-pitched sounds.

Visible light is part of the electromagnetic spectrum.
It can travel through a vacuum.