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PHYSICS GENERAL QUESTIONS FOR PRACTICE
1. Suggest one reason why on hot day, heat loses in mains electricity transmission lines may generally be greater than on a cold day. (1mk)
2. Why is a gap left between one end of a metal bridge and the end of a road leading to
the bridge (1mk)
3. Why does a person weaving dump clothes feel cold on a strong wind (2mks)
4. A bullet of mass 0.8g traveling at 400m/s is stepped by a concrete wall. Calculate the
amount of heat energy transferred to the wall. (2mks)
5. The figure below shows a uniform metre rule on equilibrium.
(i) What is the significance of the word uniform metre rule (1mk)
(ii) Determine the weight of the metre rule (2mks)
6. An object is projected vertically upwards at a speed of 15ms-1. How long will it take to
return to the same level of projection? (3mks)
7. A boy pulls the handle of a lawn mower at an angle of 30o to the horizontal with a force
of 120N. Calculate the work done when the mower moves through a distance of 12.8m. (3mks)
8. State Hooke’s law (1mk)
9. A force of 20N causes a wire to stretch by 40mm. calculate the energy stored on the
100mm wire when stretched 50mm (3mks)
10. State two ways of increasing the strength of an electromagnet (2mks)
11. The diagram shows capacitors in parallel connected to 4V battery
(i) Calculate the total capacitance (2mks)
(ii) What is the energy stored on the capacitors (3mks)
12. Show that a body falling from a height h hits the ground with energy E = ½ mv2 (3mks)
13. (a) State Hooke’s law (1mk)
(b) A force of 50N stretches a spring by 60mm. what force will extend by 20mm (3mks)
(c) Calculate the work required to stretch the spring by 40mm (3mks)
(d) If the diameter of the spring is 14mm, calculate the stress provided when the force
of 100N is applied. (3mks)
14. A bullet is fired horizontally from a cliff at a velocity 100ms-1. It takes 10 seconds to
hit the ground.
(i) Sketch the graph of height against time for the motion (2mks)
(ii) Calculate the height of the cliff (2mks)
(iii) What is the horizontal distance moved form the cliff when the bullet hits the ground (3mks)
(iv) Determine the velocity and direction with which the bullet hits the ground (3mks)
15. A crane lifts a load of 2000kg though a vertical distance of 3.0m in 6 seconds.
(a) Determine the
(i) Work done (2mks)
(ii) Power developed by the crane (2mks)
(iii) Efficiency of the crane given that it is operated by an electric motor rated 12.5Kw
(b) In an experiment to determine the specific latent heat of vaporization of matter, steam
at 100oC was passed into water contained in a well lagged copper calorimeter. The
following results were made:
Mass of calorimeter = 50g
Initial mass of water= 70g
Initial temperature of water = 5oC
Final mass of calorimeter + condensed steam = 123g
Final temperature of mixture = 30o
Specific heat capacity f water = 5200JKg-1K-1 and specific heat capacity for copper = 390JKg-1U-1)
Determine the; (a) Mass of condensed steam (1mk)
(b) Heat gained by the calorimeter (4mks)
(c) Specific latent heat of vaporization of steam (3mks)
16. Distinguish between soft and hard magnetic materials (2mks)
17. (a) Define the following terms (i) Mechanical advantage
(ii) Velocity ration
(iii) Efficiency
(b) Draw a diagram of a pulley system having
(i) Velocity ratio of 5 (3mks)
(ii) The pulley system above is used to raise a lead of 100N through a distance of 5cm.
The system is 80% efficient.
Calculate; (i) The effort (4mks)
(ii) The work done (3mks)
18. (a) State the principle of moments (1mk)
(b) A uniform plan of length 6m is pivoted at the centre to make a see saw. A weight of
200N acts at one end. A body weighing 500N moves towards the pivot on the plank as shown.
How far will the boy have to move from the pivot, for the see-saw to balance? (3mks)
19. A string vest keeps a person warm though it is a collection of holes bounded by strings.
Explain (2mks)
20. Which property of waves explains why sounds are easier t hear at night (1mk)
21. Three resistors are connected as shown at the figure below.
Determine the potential difference between A and B (3mks)
22. A wise cyclist will carry a load on the bicycle’s carrier and not in a rack sack on his
back. Explain (2mks)
23. Give a reason why tungsten is performed as target material in the X-ray tube. (1mk)
24. An object weighs 0.56N in air and 0.42N when wholly immersed in water. Calculate
the density of the object. (Density of water = 1×103kgm-3) (3mks)
25. The conductivity of a metallic conductor decreases with increase in temperature whereas
the conductivity of a semi-conductor increases with increase in temperature. Explain (2mks)
26. Light of frequency 6.0x 1014Hz strikes a sodium surface of work function 3.68 x 10-19J.
Calculate the maximum energy with which electrons are emitted.
(Planks constant = 6.6 x 10-34J) (3mks)
27. Use the kinetic theory to explain the behavior of illuminated smoke floating in air (2mks)
29. Find the quantity of heat required to change ice at -10oC to water at 0oC (3mks)
30. The pattern below shows oil leakage on a path at the rate of 10drops per second form a lorry.
(a) Calculate the initial and final velocity (3mks)
(b) Calculate the acceleration of the lorry (2mks)
