To reduce the power loss; high voltage implies low current hence power loss is reduced P = I²R
Kavungya answered the question on May 31, 2019 at 15:09
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The diagram below shows part of a waveform. The numbers on the diagram show scales in metres; if the speed of the wave is 20ms¯¹,...
(Solved)
The diagram below shows part of a waveform. The numbers on the diagram show scales in metres; if the speed of the wave is 20msˉ¹, determine the frequency and wavelength of the wave.
Date posted:
May 31, 2019
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Answers (1)
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A student designed an a.c. generator which produces a current of 10A at a p.d. of 340V. State two ways in which he can improve...
(Solved)
A student designed an a.c. generator which produces a current of 10A at a p.d. of 340V. State two ways in which he can improve his generator to increase the p.d. output.
Date posted:
May 31, 2019
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Answers (1)
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A Bunsen burner flame brought near to the cap of a charged electroscope causes the divergence of the leaf to decrease. Explain these observations.
(Solved)
A Bunsen burner flame brought near to the cap of a charged electroscope causes the divergence of the leaf to decrease. Explain these observations.
Date posted:
May 31, 2019
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Answers (1)
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Explain why sound cannot be heard from far when one shouts in a forest.
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Explain why sound cannot be heard from far when one shouts in a forest.
Date posted:
May 31, 2019
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Answers (1)
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The figure below shows the trace of a signal on CRO.
Given that the time base is set at 100ms/div., determine the frequency of the signal.
(Solved)
The figure below shows the trace of a signal on CRO.
Given that the time base is set at 100ms/div., determine the frequency of the signal.
Date posted:
May 31, 2019
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Answers (1)
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The diagram below shows the image formed by a convex mirror. Complete the diagram to show the position of the object.
(Solved)
The diagram below shows the image formed by a convex mirror. Complete the diagram to show the position of the object.
Date posted:
May 31, 2019
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Answers (1)
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A body of mass 5kg is attached to the end of a string of length 50cm and whirled continuously in a horizontal circle. If the...
(Solved)
A body of mass 5kg is attached to the end of a string of length 50cm and whirled continuously in a horizontal circle. If the tension in the string is 81N determine the angular velocity of the body
Date posted:
May 31, 2019
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Answers (1)
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A pulley system having a velocity ratio of 4 is used to raise a load of 80N through a height of 0.6m at a constant...
(Solved)
A pulley system having a velocity ratio of 4 is used to raise a load of 80N through a height of 0.6m at a constant speed using an effort of 20N in a time of 15 seconds. Calculate the power developed by the effort
Date posted:
May 31, 2019
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Answers (1)
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A spring with a spring constant of 68N/M stretches by 0.22m when a force is applied on it. Determine the energy stored in the stretched...
(Solved)
A spring with a spring constant of 68N/M stretches by 0.22m when a force is applied on it. Determine the energy stored in the stretched spring.
Date posted:
May 31, 2019
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Answers (1)
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A bullet of mass 20g travelling at 400m/s is strapped by a concrete wall. calculate the amount of energy transferred to the wall
(Solved)
A bullet of mass 20g travelling at 400m/s is strapped by a concrete wall. calculate the amount of energy transferred to the wall
Date posted:
May 31, 2019
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Answers (1)
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Name a device that is used to convert sound energy to electrical energy
(Solved)
Name a device that is used to convert sound energy to electrical energy
Date posted:
May 31, 2019
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Answers (1)
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Distinguish between velocity ratio and mechanical advantage
(Solved)
Distinguish between velocity ratio and mechanical advantage
Date posted:
May 31, 2019
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Answers (1)
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A body weighs 40N in air, 30N in water and 35N when in liquid X. Find the relative density of liquid X
(Solved)
A body weighs 40N in air, 30N in water and 35N when in liquid X. Find the relative density of liquid X
Date posted:
May 31, 2019
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Answers (1)
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A constant mass of hydrogen gas occupies a volume of 4.0cm3 at a pressure of 2.4x105 Pa and temperature of 288k. Find its volume at...
(Solved)
A constant mass of hydrogen gas occupies a volume of 4.0cm3 at a pressure of 2.4x105 Pa and temperature of 288k. Find its volume at a pressure of 1.6x105Pa when the temperature is 293K
Date posted:
May 31, 2019
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Answers (1)
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Two liquids of density 1100kg/m3 and 850kg/m3 are mixed in equal volumes. The mixture fills a tank of 300cmx 40cm x 50cm to the bring...
(Solved)
Two liquids of density 1100kg/m3 and 850kg/m3 are mixed in equal volumes. The mixture fills a tank of 300cmx 40cm x 50cm to the bring calculate the mass of each liquid
Date posted:
May 31, 2019
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Answers (1)
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A vessel weighs 90g and has a specific heat capacity of 420J/Kg/K. Calculate its heat capacity
(Solved)
A vessel weighs 90g and has a specific heat capacity of 420J/Kg/K. Calculate its heat capacity
Date posted:
May 31, 2019
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Answers (1)
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A crane just lifts 9940N when an effort of 116N is applied. Find its velocity ratio if the crane has an efficiency of 72%
(Solved)
A crane just lifts 9940N when an effort of 116N is applied. Find its velocity ratio if the crane has an efficiency of 72%
Date posted:
May 31, 2019
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Answers (1)
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An oil drop forms a circular patch of area 5x10-3m2. If the oil drop has a volume of 9x10-12M2, calculate the thickness of the oil...
(Solved)
An oil drop forms a circular patch of area 5x10-3m2. If the oil drop has a volume of 9x10-12M2, calculate the thickness of the oil molecule.
Date posted:
May 31, 2019
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Answers (1)
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A concave mirror of focal length 20 cm forms a real image three times the size of the object. If the object height is 4cm;determine,...
(Solved)
A concave mirror of focal length 20 cm forms a real image three times the size of the object. If the object height is 4cm;
determine, using graphical method, the:
i) object distance
ii) The image distance
Date posted:
May 31, 2019
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Answers (1)
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A Power station has an input of 30kw at a potential difference of 5kv.A transformer with a secondary coil of 1000 turns is used to...
(Solved)
A Power station has an input of 30kw at a potential difference of 5kv.A transformer with a secondary coil of 1000 turns is used to step down the voltage to 1000v for transmission along a grid .Assuming there are no power loses in the transformer .calculate.
i) current in the primary coil
ii) The number of turns in the primary coil
iii) The current in the secondary coil
iv) State which of the coils is thick and why
Date posted:
May 31, 2019
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Answers (1)