E=hf =6.63x10-9Jsx3x1016Hz
=1.989x10-17J
Moraa orina answered the question on April 12, 2018 at 06:38
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State the uses of X-Rays
(Solved)
State the uses of X-Rays.
Date posted:
April 12, 2018
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Answers (1)
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Explain how X-Rays are produced
(Solved)
Explain how X-Rays are produced
Date posted:
April 12, 2018
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Answers (1)
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State the uses of the Cathode Ray Oscilloscope (CRO)
(Solved)
State the uses of the Cathode Ray Oscilloscope (CRO)
Date posted:
April 12, 2018
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Answers (1)
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State the components of a cathode ray oscilloscope
(Solved)
State the components of a cathode ray oscilloscope
Date posted:
April 12, 2018
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Answers (1)
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An electric cooker has an oven rated 3 kW, a grill rated 2 kW and two rings each rated 500 W. The cooker operates from a 240V...
(Solved)
An electric cooker has an oven rated 3 kW, a grill rated 2 kW and two rings each rated 500 W. The cooker
operates from a 24 0V mains. What is the cost of operating all the parts for 5 minutes if electricity costs Sh 1.50 per unit?
Date posted:
April 11, 2018
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Answers (1)
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A six bulb arrangement in a house runs for 8 hours every night for 5 days. If each bulb is rated 100 W and the cost of...
(Solved)
A six bulb arrangement in a house runs for 8 hours every night for 5 days. If each bulb is rated 100 W and the cost of electrical energy is sh. 2.60 per unit, how much will the owner of the house pay at the end of the five days?
Date posted:
April 11, 2018
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Answers (1)
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An electric cooker has an oven rated 3kW, a grill rated 2kW and two rings each rated 500W. The cooker operates from 240V...
(Solved)
An electric cooker has an oven rated 3kW, a grill rated 2kW and two rings each rated 500W. The cooker
operates from 240V mains. Would a 5A fuse be suitable for the cooker assuming that all the parts are switched
on?
Date posted:
April 11, 2018
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Answers (1)
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A power station produces 50kW at 240V. The power is transmitted through cables with a resistance of 0.4?. Calculate the percentage power loss during...
(Solved)
A power station produces 50kW at 240V. The power is transmitted through cables with a resistance of
0.4?. Calculate the percentage power loss during transmission.
Date posted:
April 11, 2018
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Answers (1)
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Some length of a power line has a resistance of 10? and is transmitting 11kV and a current of 1A. If the
voltage is stepped...
(Solved)
Some length of a power line has a resistance of 10Ω and is transmitting 11kV and a current of 1A. If the
voltage is stepped up to 160kV by a transformer, calculate:
a) The initial power loss
b) The power loss after step up
Date posted:
April 11, 2018
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Answers (1)
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State the main causes of energy losses in transformers:
(Solved)
State the main causes of energy losses in transformers:
Date posted:
April 11, 2018
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Answers (1)
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A student designed a transformer to supply a current of 10A at a potential difference of 60V to an electric motor from an ac supply...
(Solved)
A student designed a transformer to supply a current of 10A at a potential difference of 60V to an electric motor from an ac supply of 240V. if the efficiency of the transformer is 80%, calculate:
a) The power supplied to the transformer.
b) The current in the primary coil
Date posted:
April 11, 2018
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Answers (1)
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Calculate the number of turns of the secondary coil of a step down transformer which would enable a 12V bulb
to be used with a...
(Solved)
Calculate the number of turns of the secondary coil of a step down transformer which would enable a 12V bulb
to be used with a 240V ac supply if there are 480 turns in the primary coil.
Date posted:
April 11, 2018
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Answers (1)
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State the applications of electromagnetic induction
(Solved)
State the applications of electromagnetic induction
Date posted:
April 11, 2018
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Answers (1)
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An X-ray machine produces a radiation of wavelength 1.0x10-11m. calculate:
a) The frequency of the radiation.
b) The energy content of the radiation.
(Solved)
An X-ray machine produces a radiation of wavelength 1.0x10-11m. calculate:
a) The frequency of the radiation.
b) The energy content of the radiation.
Date posted:
April 11, 2018
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Answers (1)
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A radio transmitter produces waves of frequency 1.0x108Hz. Calculate the wavelength of the signal.
(Solved)
A radio transmitter produces waves of frequency 1.0x108Hz. Calculate the wavelength of the signal.
Date posted:
April 11, 2018
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Answers (1)
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A cyclist who is travelling at 20m/s negotiates a bend of radius 45m. he inclines at an angle O to the
vertical. Calculate:
a) The centripetal...
(Solved)
A cyclist who is travelling at 20m/s negotiates a bend of radius 45m. he inclines at an angle Ɵ to the
vertical. Calculate:
a) The centripetal acceleration
b) The angle of inclination Ɵ
Date posted:
April 11, 2018
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Answers (1)
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The maximum speed at which a motorist can negotiate a corner on a level ground is 20m/s. if the radius
of the curve is 100m,...
(Solved)
The maximum speed at which a motorist can negotiate a corner on a level ground is 20m/s. if the radius
of the curve is 100m, calculate:
a) The coefficient of friction, μ
b) The angle at which the road should be banked to enable the motorist negotiate the corner at a critical
speed of 20m/s.
Date posted:
April 11, 2018
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Answers (1)
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A bob of mass 1kg is moving in a uniform circular path in a vertical plane of radius 1m. If it is whirled at...
(Solved)
A bob of mass 1kg is moving in a uniform circular path in a vertical plane of radius 1m. If it is whirled at a
frequency of 2 cycles per second, calculate:
a) The tension in the string when the bob is at the top part of the circle
b) Tension when it is at the bottom
c) At what position is the string likely to break? Why?
d) What is the minimum speed required to maintain the string under tension.
Date posted:
April 11, 2018
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Answers (1)
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An object of mass 0.4kg is rotated by a string at a constant speed, v in a vertical circle of radius 1m. If the
minimum...
(Solved)
An object of mass 0.4kg is rotated by a string at a constant speed, v in a vertical circle of radius 1m. If the
minimum tension in the string is 3N, calculate :
a) The speed, v
b) Maximum tension in the string
c) The tension when the string is just horizontal
Date posted:
April 11, 2018
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Answers (1)
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An object of mass 8kg is whirled round rapidly in a vertical circle of radius 2m with a constant speed of
6m/s. Calculate the maximum...
(Solved)
An object of mass 8kg is whirled round rapidly in a vertical circle of radius 2m with a constant speed of
6m/s. Calculate the maximum and minimum tension in the string. Take g=10N/kg
Date posted:
April 11, 2018
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Answers (1)