Science and Technology

a.

If an experiment is done to find how various amount of fertilizers effect the height of tomato plant, what is the independent variable in this experiment?

(i) Height of tomato plant

(ii) Amount of fertilizer

(iii) Amount of water

(iv) Type of soil

[1 mark]

b.

Which of the following statements is true about baseband transmission is true?

(i) Digital signals are converted to analog signals and sent to the channel.

(ii) Separate channels are used for sending and receiving signals.

(iii) Sending and receiving signals are done in the same channel simultaneously.

(iv) Generally, it is used for long distance communication.

[1 mark]

c.

How does plantation of trees help reduce the effect of climate change?

(i) By increasing oxygen level in the atmosphere

(ii) By reducing the amount of carbon dioxide through photosynthesis

(iii) By lowering the temperature of the environment.

(iv) By making a lot of rainfall

[1 mark]

d.

If the weight of an object on the surface of the Moon is 66 N, what might be the weight of the object on Earth? (Acceleration due to gravity of Moon is $1.62 m/s^2$ )

(i) 396 N

(ii) 66 N

(iii) 11 N

(iv) 6.6 N

[1 mark]

e.

How much force is produced in piston Q in the given figure?

(i) 80 N

(ii) 100 N

(iii) 400 N

(iv) 500 N

[1 mark]

f.

What is called the effect of heat on the volume of an object?

(i) thermal expansion

(ii) thermal conduction

(iii) thermal equilibrium

(iv) thermal radiation

[1 mark]

g.

If a transformer has more turns in the secondary winding than in the primary winding, which of the following statements is correct?

(i) It does not change A.C. voltage.

(ii) It decreases A.C. voltage.

(iii) It increases A.C. voltage.

(iv) It increases A.C. voltage according to the situation.

[1 mark]

h.

Which of the following shows the correct order of the atomic radii of the elements nitrogen, oxygen and fluorine?

(i) O < R < N

(ii) N < F < O

(iii) O < N < F

(iv) F < O < N

[1 mark]

i.

Which is the correct order of metal processing for their purification?

(i) Concentration, Oxidation, Refining, Reduction

(ii) Concentration, Reduction, Oxidation, Refining

(iii) Concentration, Reduction, Refining, Oxidation

(iv) Concentration, Oxidation, Reduction, Refining

[1 mark]

j.

Which of the following is a fungicide?

(i) Cypermethrin

(ii) Carbendazim

(iii) Butachlor

(iv) Zinc Phosphide

[1 mark]