What exactly are shadows?

• AN IMAGE WITH COLOURS

• When an opaque object comes in the path of light

• An plain image

Answer explanation

Ans. The dark area formed behind the opaque object, when the light from light source is blocked by it is called shadow.

What do green plants use during photosynthesis?

• Hydrogen
• Carbon dioxide
• Nitrogen
• Oxygen
• Light Energy of the sun

Answer explanation

Ans. We see reflection of our face in the mirror. We also see reflections of other objects that are in front of the mirror.

What two essential things does photosynthesis produce?

• (a) Starch and oxygen

• (b) Heat and light

• (c) Water and carbon dioxide

• (d) Nitrogen and hydrogen

Where does the energy in wood burning for cooking or warmth come from?

• Photosynthesis
• Wind power
• We utilise Sun's energy locked in plants

• Nuclear fusion

How did the energy in fossil fuels like coal and gas get there?

• From the energy of the sun
• From the remains of aliens who visited Earth
• From light energy of the Sun. From the remains of plants and animals that lived millions of years ago.

• From the core of the Earth

Which one of the following is NOT directly dependent on sunlight energy?

• Electricity
• Solar panels
• Photosynthesis
• Wind energy

How far apart were Galileo and his assistant when they attempted to measure the speed of light?

• (a) A few meters

• (b) Around one kilometer

• (c) Several kilometers

• (d) It's not mentioned in the passage.

What did Galileo and his assistant hold in their hands?

• (a) Telescopes

• (b) Stopwatches

• (c) Lanterns with shutters

• (d) Mirrors

How did Galileo's assistant know when to open their lantern's shutter?

• (a) By following a pre-arranged signal

• (b) By counting to a specific number

• (c) By seeing Galileo's lantern flash

• (d) It's not explained in the passage.

What did Galileo expect to find by dividing the distance between them by the measured time?

• (a) The distance to the nearest star

• (b) The age of the universe

• (c) The size of the Earth

• (d) The speed of light