Explanation

• Electrons are negatively charged particles outside the nucleus.
• They move in energy levels (shells) around the nucleus.
• Chemical bonding occurs due to sharing or transfer of electrons.
• Protons and neutrons remain inside the nucleus.

Last verified on 24-05-2026

Explanation

• Thermal power plants generate electricity using heat energy.
• Fuel combustion (coal, gas, oil) produces heat.
• This heat is used to produce steam that drives turbines.
• Turbines convert mechanical energy into electrical energy.

Last verified on 24-05-2026

Explanation

The energy of a photon is calculated using the formula E = hf, where:

• h = Planck’s constant
• f = frequency of the photon

This shows that photon energy is directly proportional to its frequency.

Last verified on 23-05-2026

Explanation

• When frequency is above the threshold, electrons are emitted from the metal surface.
• Increasing intensity means more photons fall on the surface, so more electrons are emitted.

Last verified on 23-05-2026

Explanation

• Highest tides are called Spring tides.
• They occur when the Sun, Earth, and Moon are aligned in a straight line.
• Their gravitational forces combine and produce very high and very low tides.

Last verified on 23-05-2026

Explanation

• The transport sector uses energy mainly for running vehicles like cars, buses, trucks, trains, and airplanes.
• It depends mostly on petroleum fuels such as petrol, diesel, and CNG.
• This sector is one of the largest consumers of fossil fuels worldwide.

Last verified on 23-05-2026

Explanation

• Natural gas is commonly used in homes for cooking food and heating water or rooms.
• It is a fossil fuel mainly composed of methane gas.
• It burns cleaner than coal and oil.
• It producing less smoke and pollution.

Last verified on 23-05-2026

Explanation

• Hydroelectric energy uses flowing or falling water to rotate turbines and generate electricity.
• Dams are commonly built on rivers for hydroelectric power production.
• It is one of the oldest and clean renewable energy sources.

Last verified on 23-05-2026

Explanation

• The cell membrane is a thin protective layer surrounding the cell.
• It controls the movement of substances into and out of the cell.
• It is also called the plasma membrane.
• It is selectively permeable.

Last verified on 23-05-2026

Explanation

• Proteins are called body-building foods.
• They help in growth, repair of tissues, and muscle development.
• They are essential for maintaining and rebuilding body cells.
• They are made of amino acids, the building blocks of the body.
• Deficiency of protein can lead to weak muscles and poor growth.

Last verified on 06-05-2026