Explanation

• Body-building nutrients are essential for growth and repair of tissues.
• The main body-building nutrient is proteins.
• Lack of proteins in children leads to poor growth and weakness.
• Protein deficiency is most directly linked to impaired body development.

Last verified on 08-05-2026

Explanation

• Laser light has special properties that make it highly useful in science and technology.
• It travels in a very narrow and straight path.
• This property is called directionality (or high collimation).
• It allows the beam to stay focused over long distances.
• That is why lasers are used in cutting, communication, and medical tools.

Last verified on 08-05-2026

Explanation

• Atoms are classified based on atomic number and mass number.
• When atoms of different elements have the same mass number, they are called isobars.
• Mass number = protons + neutrons.
• Isobars have different atomic numbers but equal mass numbers.
• They are not chemically identical elements.

Last verified on 08-05-2026

Explanation

• Radioactive emissions include alpha, beta, and gamma rays.
• Charged particles are deflected in electric and magnetic fields.
• Neutral radiation does not show deflection.
• Gamma rays are electromagnetic waves with no charge.
• Therefore, they pass straight without deviation.

Last verified on 08-05-2026

Explanation

• Atoms with the same atomic number but different mass numbers are called isotopes.
• Atomic number depends on the number of protons.
• Mass number depends on protons + neutrons.
• So, difference in mass number comes from variation in neutrons.
• Isotopes have similar chemical properties but different physical properties.

Last verified on 08-05-2026

Explanation

• Energy sources are classified as renewable and non-renewable.
• Some sources depend on natural conditions like sunlight or wind.
• Others can produce electricity continuously if fuel is available.
• Natural gas is a reliable dispatchable energy source.
• It can generate power anytime under normal fuel supply.

Last verified on 08-05-2026

Explanation

• Photon energy depends on the frequency of light.
• Higher frequency means higher energy.
• This relation was explained by Max Planck.
• Photon is a tiny packet of light energy.

Last verified on 07-05-2026

Explanation

• In the photoelectric effect, light ejects electrons from a metal surface.
• Increasing light intensity increases the number of photons hitting the surface.
• More photons release more electrons.
• The photoelectric effect supported the quantum theory of light.
• Albert Einstein received the Nobel Prize for explaining this effect.

Last verified on 07-05-2026

Explanation

• Neap tides occur when the Sun and Moon pull Earth’s water from different directions.
• This happens when the Moon is at a right angle (90°) to the Earth-Sun line.
• During neap tides, the difference between high and low tide is small.
• Neap tides occur twice every lunar month.
• Spring tides happen during full moon and new moon phases.

Last verified on 07-05-2026

Explanation

• Industrial growth increases the use of machines and factories.
• Factories require large amounts of electricity for production.
• Therefore, industrial expansion directly raises electricity demand.

Industries use electricity for:

• Manufacturing
• Machinery operation
• Cooling and heating systems
• Production lines

Last verified on 07-05-2026