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- What is a machine?(Solved)
What is a machine?
Date posted: May 31, 2019. Answers (1)
- The figure below shows a master cylinder sealed at one end. Instead of brake fluid, the cylinder contains air.
When a force is applied to the...(Solved)
The figure below shows a master cylinder sealed at one end. Instead of brake fluid, the cylinder contains air.
When a force is applied to the piston, the length d changes from 6.0cm to 4.0cm. The pressure of the air increases but the temperature stays constant.
(i) Describe how the molecules of air exert a pressure.
(ii) Explain why the pressure increases even though the temperature stays constant.
(iii) The initial pressure of the air inside the cylinder is 1.0 x 105 pa. Calculate the final pressure of the air.
Date posted: May 31, 2019. Answers (1)
- State one advantage of alcohol thermometer over mercury thermometer.(Solved)
State one advantage of alcohol thermometer over mercury thermometer.
Date posted: May 31, 2019. Answers (1)
- The figure below shows a car braking system. The brake fluid is an oily liquid.
The brake drum rotates with the wheel of the car.
(i) Explain...(Solved)
The figure below shows a car braking system. The brake fluid is an oily liquid.
The brake drum rotates with the wheel of the car.
(i) Explain how pushing the brake pedal makes the brake rub against the drum.
(ii) The cross-sectional area of the master piston is 2.0cm2. A force of 140N is applied to the master piston.
(I) Calculate the pressure created in the brake fluid by the master piston.
(II) The cross-sectional area of each slave piston is 2.8cm2. Calculate the force exerted on each slave piston by the brake fluid.
(III) The force exerted on the master piston is greater than the force applied by the foot on the brake pedal. Using the principle of moments, explain this
Date posted: May 31, 2019. Answers (1)
- The figure below shows two containers filled with two different liquids to the same height.
It was found that the pressure at the bottom of A...(Solved)
The figure below shows two containers filled with two different liquids to the same height.
It was found that the pressure at the bottom of A is greater than that at B. Explain
Date posted: May 31, 2019. Answers (1)
- A rubber tube is inflated to pressure of 2.7 x 105 pa and volume 3800cm3 at temperature of 250C. It is then taken to another...(Solved)
A rubber tube is inflated to pressure of 2.7 x 105 pa and volume 3800cm3 at temperature of 250C. It is then taken to another place where the temperature is 150C and the pressure is 2.5 x 105 pa. Determine the new volume
Date posted: May 31, 2019. Answers (1)
- The figure shows a manometer used to measure the pressure difference between the air inside a plastic container and the atmosphere outside.
Calculate the force F...(Solved)
The figure shows a manometer used to measure the pressure difference between the air inside a plastic container and the atmosphere outside.
Calculate the force F exerted on the container.
Date posted: May 31, 2019. Answers (1)
- The figure below shows a bottle opener.
A force of 30N is applied at a distance of 11cm from the pivot P. The force F on...(Solved)
The figure below shows a bottle opener.
A force of 30N is applied at a distance of 11cm from the pivot P. The force F on the bottle cap of 1.5cm from the pivot P. Calculate the force F on the edge of the cap.
Date posted: May 31, 2019. Answers (1)
- A transformer is designed to supply a current of 12A at a p.d. of 80V. The inlet cable is to be connected to an a.c....(Solved)
A transformer is designed to supply a current of 12A at a p.d. of 80V. The inlet cable is to be connected to an a.c. mains of
240V. The efficiency of this transformer is 80%.
Calculate
i) Current in the transformer.
ii) The power supplied to the transfer.
Date posted: May 30, 2019. Answers (1)
- Explain the term work function of a metal surface, stating how it affect photoelectric emission.(Solved)
Explain the term work function of a metal surface, stating how it affect photoelectric emission.
Date posted: May 30, 2019. Answers (1)
- State one similarity between ultraviolet rays and gamma rays in terms of their dangers.(Solved)
State one similarity between ultraviolet rays and gamma rays in terms of their dangers.
Date posted: May 30, 2019. Answers (1)
- Consider the table below for electromagnetic waves.
Fill in the spaces labelled A, B, C & D(Solved)
Consider the table below for electromagnetic waves.
Fill in the spaces labelled A, B, C & D
Date posted: May 30, 2019. Answers (1)
- A 2kW electric heater is used for 10 hrs. Calculate the cost of electricity if its costs Kshs 30 per unit.(Solved)
A 2kW electric heater is used for 10 hrs. Calculate the cost of electricity if its costs Kshs 30 per unit.
Date posted: May 30, 2019. Answers (1)
- A heater is rated 3kW, 240V. The fuses available are marked 10A, 13A and 20A. Which fuse is most suitable?(Solved)
A heater is rated 3kW, 240V. The fuses available are marked 10A, 13A and 20A. Which fuse is most suitable?
Date posted: May 30, 2019. Answers (1)
- Figure below shows a modern mains appliance.
i) State the purpose of lead E.
ii) Explain why the fuse is connected to the live wire.(Solved)
Figure below shows a modern mains appliance.
i) State the purpose of lead E.
ii) Explain why the fuse is connected to the live wire.
Date posted: May 30, 2019. Answers (1)
- The figure below shows a pin 60mm long placed a long the principal axis of a lens of focal length 50mm. The near end of...(Solved)
The figure below shows a pin 60mm long placed a long the principal axis of a lens of focal length 50mm. The near end of the pin is 80mm form the lens.
Determine the length of the image.
Date posted: May 30, 2019. Answers (1)
- i)The figure below shows an object 'O' in front of a lens.
By drawing appropriate rays, on the same figure, state the position of the image...(Solved)
i)The figure below shows an object 'O' in front of a lens.
By drawing appropriate rays, on the same figure, state the position of the image formed.
ii) Explain the adjustment you would make on the position of the object above in order to obtain a real magnified image.
Date posted: May 30, 2019. Answers (1)
- When does a convex lens form a virtual image?.(Solved)
When does a convex lens form a virtual image?.
Date posted: May 30, 2019. Answers (1)
- The figure below shows a waver profile for a wave whose frequency is 2HZ
Determine the value of t3(s)(Solved)
The figure below shows a waver profile for a wave whose frequency is 2HZ
Determine the value of t3(s)
Date posted: May 30, 2019. Answers (1)
- Sound is a longitudinal pressure wave. Explain this statement.(Solved)
Sound is a longitudinal pressure wave. Explain this statement.
Date posted: May 30, 2019. Answers (1)