Class 8 (Dashain assignment)

 

Section A: Short-answer questions

Answer each question in 3–5 sentences.

1.     Differentiate between elements, compounds, and mixtures with two examples of each.

2.     What is photosynthesis? Write its word equation and explain its importance.

3.     Explain the differences between physical and chemical changes with two examples of each.

4.     What is pressure? Write its formula and mention two factors affecting pressure in solids.

5.     Differentiate between renewable and non-renewable sources of energy.

6.     What is a simple machine? Explain the functions of a lever, pulley and inclined plane.

7.     Explain the difference between series and parallel electric circuits.

8.     What are acids and bases? Give two examples of each and mention one use of each.

9.     Explain how air pollution affects human health and the environment.

10.  What is heredity? How do parents transfer characteristics to their offspring?

Section B: Multiple-choice questions

Choose the correct answer.

1. Which gas is released during photosynthesis?

A. Carbon dioxide

B. Oxygen

C. Nitrogen

D. Hydrogen

2. What is the SI unit of pressure?

A. Newton

B. Joule

C. Pascal

D. Watt

3. Which substance turns blue litmus paper red?

A. Acid

B. Base

C. Salt solution only

D. Pure water

4. Which material is a good electrical conductor?

A. Rubber

B. Glass

C. Copper

D. Plastic

5. Which organelle controls most activities of a cell?

A. Vacuole

B. Nucleus

C. Cell wall

D. Cytoplasm

6. Which energy source is renewable?

A. Coal

B. Petrol

C. Diesel

D. Solar energy

7. Which instrument measures electric current?

A. Voltmeter

B. Ammeter

C. Thermometer

D. Barometer

8. Which process changes liquid water into water vapour?

A. Freezing

B. Condensation

C. Evaporation

D. Melting

Section C: Numerical problems

Show the formula, calculation and final answer with units.

1.     A force of 200 N acts on a surface of area 4 m². Calculate the pressure exerted.

2.     A student travels 300 metres in 60 seconds. Calculate the student's average speed.

3.     An electric appliance operates at 220 V and draws a current of 2 A. Calculate its electrical power.

4.     A machine performs 600 J of work in 20 seconds. Calculate its power.

Section D: Diagram and practical work

1.     Draw and label a plant cell and an animal cell. Write two differences between them.

2.     Draw a simple electric circuit containing a cell, switch, bulb and connecting wires.

3.     Prepare a table of five household substances, predicting whether each is acidic, basic or neutral. Do not taste or mix unknown substances.