Explanation

• CFCs, carbon dioxide (CO₂), and methane (CH₄) are all greenhouse gases.
• Carbon dioxide traps heat in the atmosphere and increases temperature.
• Methane is a very strong greenhouse gas with high warming effect.
• CFCs also damage the ozone layer and act as greenhouse gases.

Last verified on 16-06-2026

Explanation

• Density is the reciprocal of specific volume.
• Density tells how much mass is in a given volume.
• Specific volume tells how much volume is occupied by unit mass.

Last verified on 16-06-2026

Explanation

• A junction in an electrical circuit is called a node.
• A node is a point where two or more circuit elements meet.
• Current entering a node equals current leaving it (Kirchhoff’s Law).

Last verified on 16-06-2026

Explanation

• Brazing and welding are hot working processes.
• Because they involve the use of heat to join metals.
• In welding, metals are melted and joined together using heat.
• In brazing, a filler metal is melted to join two metal pieces without melting the base metals.

Last verified on 16-06-2026

Explanation

• Black colour cloth absorbs more sunlight than other colours.
• Black absorbs almost all light and converts it into heat.

Additional information:

• White colour reflects most sunlight and stays cooler.

Last verified on 16-06-2026