TWA Demo Paper

Which of the following is a chemical change?

• Melting of ice

• Boiling of water

• Burning of paper

• Dissolving salt in water

The process of converting a solid directly into a gas is called:

• Sublimation

• Condensation

• Evaporation

• Freezing

Which of the following is a greenhouse gas?

• Oxygen

• Nitrogen

• Carbon dioxide

• Helium

Which of the following is not a form of energy?

• Thermal energy

• Kinetic energy

• Sound energy

• Mass energy

The process of separation of components of a mixture based on their boiling points is called:

• Filtration

• Evaporation

• Distillation

• Chromatography

Which of the following is an example of a physical change?

• Rusting of iron

• Digestion of food

• Burning of wood

• Melting of butter

The process by which green plants make their food is called:

• Respiration

• Digestion

• Photosynthesis

• Fermentation

Which of the following is a renewable source of energy?

• Coal

• Natural gas

• Solar power

• Nuclear power

Which of the following is a primary consumer in a food chain?

• Lion

• Grasshopper

• Snake

• Tree

The SI unit of electric current is:

• Volt

• Ampere

• Ohm

• Watt