(i) The ratio of the sine of angle of incidence to the sine of angle of refraction is a constant for a pair of media
(ii) – Do not absorb light energy like mirrors
- Not affected by thickness as mirrors
- Do not wear off like the peeling of silvering on mirror.
joseph rimiru answered the question on January 7, 2018 at 17:50
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A form 4 student observed that his grandfather positions a book far from his eyes when reading it. Explain the type of lenses that the...
(Solved)
A form 4 student observed that his grandfather positions a book far from his eyes when reading it. Explain the type of lenses that the student should advice his grandfather to wear.
Date posted:
January 7, 2018
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Answers (1)
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When a new dry cell is connected in series with a 2.7 ohms resistor, a current of 0.5A flows in the circuit. Determine the internal resistance...
(Solved)
When a new dry cell is connected in series with a 2.7 ohms resistor, a current of 0.5A flows in the circuit. Determine the internal resistance of the cell.
Date posted:
January 7, 2018
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Answers (1)
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Why does a gun recoil when it is fired ?
(Solved)
Why does a gun recoil when it is fired ?
Date posted:
January 7, 2018
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Answers (1)
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Water flows along a horizontal pipe of cross-section area 35^2 cm and constriction of cross section 5^2 cm . if the speed of water...
(Solved)
Water flows along a horizontal pipe of cross-section area 35^2 cm and constriction of cross section 5^2 cm . if the speed of water at the construction is 2 m/s
Calculate:
i)Continuity constant in SI unit
ii) the speed in the wide section
Date posted:
January 7, 2018
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Answers (1)
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A boy heats 5kg of water to a temperature of 80oC. When she adds m kg of water at 15oC the mixture attains a...
(Solved)
A boy heats 5kg of water to a temperature of 80oC. When she adds m kg of water at 15oC the mixture attains a temperature of 40oC. Determine the value of m
Date posted:
January 7, 2018
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Answers (1)
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Define an echo
(Solved)
Define an echo.
Date posted:
January 6, 2018
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Answers (1)
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State the difference between lens of a camera and that of an eye.
(Solved)
State the difference between lens of a camera and that of an eye.
Date posted:
January 6, 2018
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Answers (1)
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(i) State the reason why a lamp is made of tungsten. (ii) Why is the bulb of such a lamp filled with an active gas?
(Solved)
(i) State the reason why a lamp is made of tungsten.
(ii) Why is the bulb of such a lamp filled with an active gas?
Date posted:
January 6, 2018
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Answers (1)
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A hockey player trains on a nylon fiber surface. As he runs around, his shoes rub against the surface and he becomes positively charged.
(Solved)
A hockey player trains on a nylon fiber surface. As he runs around, his shoes rub against the surface and he becomes positively charged.
(i) Explain in terms of particles involved, how he becomes positively charged.
Date posted:
January 6, 2018
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Answers (1)
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State the advantages of solid state devices over vacuum tubes
(Solved)
State the advantages of solid state devices over vacuum tubes.
Date posted:
January 6, 2018
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Answers (1)
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(a) What is diffusion? (b) A smoke cell contains a mixture of trapped air and smoke. The cell is brightly lit and viewed through a microscope. State...
(Solved)
(a) What is diffusion?
(b) A smoke cell contains a mixture of trapped air and smoke. The cell is brightly lit and viewed through a microscope. State and explain what is observed.
(c) A beaker is filled completely with water. A spoon full of common salt is added slowly. The salt dissolves and the water does not overflow.
(i) Why is salt added slowly?
(ii) Why doesn't the water overflow?
Date posted:
January 5, 2018
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Answers (1)
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A stream of air passing over a roof of room at higher velocity than the velocity of air inside the room is likely to...
(Solved)
A stream of air passing over a roof of room at higher velocity than the velocity of air inside the room is likely to blow off the roof. Give a reason for this
Date posted:
January 5, 2018
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Answers (1)
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Explain why in trying to move a rigid wall, a person is said to be doing no work at all.
(Solved)
Explain why in trying to move a rigid wall, a person is said to be doing no work at all.
Date posted:
January 3, 2018
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Answers (1)
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What is the main difference between an a.c. and d.c generators?
(Solved)
What is the main difference between an a.c. and d.c generators?
Date posted:
January 3, 2018
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Answers (1)
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Determine the cost of using an electric heater rated 3kW for 12 hours given that the cost of electricity per kilowatt-hour is Sh. 8.00.
(Solved)
Determine the cost of using an electric heater rated 3kW for 12 hours given that the cost of electricity per kilowatt-hour is Sh. 8.00.
Date posted:
January 3, 2018
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Answers (1)
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State and explain the effect of increasing the extra high tension E.H.T in an x-ray tube on the x-rays.
(Solved)
State and explain the effect of increasing the extra high tension E.H.T in an x-ray tube on the x-rays.
Date posted:
January 3, 2018
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Answers (1)
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State the function of the control grid in a cathode ray oscilloscope
(Solved)
State the function of the control grid in a cathode ray oscilloscope
Date posted:
January 2, 2018
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Answers (1)
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An electric bulb is rated ‘240V,100W .It contains a 1m long coiled tungsten wire . When switched on the wire reaches a temperature of...
(Solved)
An electric bulb is rated ‘240V,100W .It contains a 1m long coiled tungsten wire . When switched on the wire reaches a temperature of about 2500 degrees Celsius.
(i) How much energy is given out by the bulb in 1second
(ii) Why is the wire coiled?
(iii) State two properties of tungsten which make it suitable for use in electric bulbs.
Date posted:
January 2, 2018
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Answers (1)
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There are two types of seismic waves produced by earthquakes. They are called P-waves and S-waves. P-waves are longitudinal and S-waves are transverse.(a) Explain...
(Solved)
There are two types of seismic waves produced by earthquakes. They are called P-waves and S-waves. P-waves are longitudinal and S-waves are transverse.
(a) Explain what is meant by the terms longitudinal and transverse.
longitudinal
transverse
(b) State another example of a longitudinal wave, a transverse wave.
Date posted:
January 2, 2018
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Answers (1)
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A bar magnet AB is suspended freely so that it is able to rotate on a horizontal plane. It turns until end B points southwards....
(Solved)
A bar magnet AB is suspended freely so that it is able to rotate on a horizontal plane. It turns until end B points southwards. Explain how the suspended magnet can be used to identify the north pole of another unmarked magnet.
Date posted:
January 2, 2018
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Answers (1)