Explanation

• Laser light is highly concentrated in a very narrow beam.
• This allows it to deliver a large amount of energy to a very small area.
• It does not spread out like normal light.
• This property makes lasers useful in medicine, industry, and communication.

Last verified on 13-05-2026

Explanation

• Alpha radiation has the lowest penetrating power.
• It can be stopped easily by paper or even human skin.
• Alpha particles are heavy and carry a positive charge.

Additional information:

• Gamma rays have the highest penetrating power.

Last verified on 13-05-2026

Explanation

• A quantum of energy of light (electromagnetic radiation) is called a photon.

• Photon is the smallest discrete packet (bundle) of energy.

• It carries energy proportional to its frequency (E = hf).

• Photons have no mass and travel at the speed of light.

• Light shows particle nature due to photons.

Last verified on 09-05-2026

Explanation

• Photoelectric emission stops when the frequency of incident light is below the threshold frequency of the metal.

• Below this minimum frequency, electrons cannot gain enough energy to escape the metal surface.

• Each metal has its own threshold frequency.

• This effect supports the quantum theory of light.

Last verified on 09-05-2026

Explanation

• Spring tides occur when the Earth, Moon, and Sun are in a straight line (aligned).

• This happens during New Moon and Full Moon phases.

• The gravitational pull of the Moon and Sun combines, producing very high and very low tides.

• Spring tides are not related to seasons like spring; the name refers to “jumping or rising” tides.

• They occur about twice a month.

Last verified on 09-05-2026