Topping:- The addition of distilled water into a lead acid accumulator to improve on the ion
concentration.
Dopping:- Addition of impurities to an intrinsic semiconductors to improve on its conductivity.
sharon kalunda answered the question on April 5, 2019 at 11:03
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Figure shows a voltmeter connected across the cell. The voltmeter reads 1.5V when the
switch S, is open and 1.25V when the switch is closed.
(Solved)
Figure shows a voltmeter connected across the cell. The voltmeter reads 1.5V when the
switch S, is open and 1.25V when the switch is closed.
i) What is the e.m.f of the cell?
ii) What is the terminal voltage of the cell?
iii) Calculate the internal resistance of the cell
Date posted:
April 5, 2019
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Answers (1)
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Distinguish between a p- type and an n- type extrinsic semiconductors
(Solved)
Distinguish between a p- type and an n- type extrinsic semiconductors
Date posted:
April 5, 2019
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Answers (1)
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Explain why eight 1.5V cells arranged in series to give a total of 12V cannot be used to start
a car. But car battery of 12V...
(Solved)
Explain why eight 1.5V cells arranged in series to give a total of 12V cannot be used to start
a car. But car battery of 12V starts a car
Date posted:
April 5, 2019
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Answers (1)
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Figure below shows a circle with two diodes P and Q and a cell:-
(Solved)
Figure below shows a circle with two diodes P and Q and a cell:-
Explain the observation which would be made if S is closed
Date posted:
April 5, 2019
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Answers (1)
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Explain how conductivity of a semiconductor changes with increase in temperature
(Solved)
Explain how conductivity of a semiconductor changes with increase in temperature
Date posted:
April 5, 2019
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Answers (1)
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The figure below shows a circuit diagram for full wave rectification
(Solved)
The figure below shows a circuit diagram for full wave rectification
Draw the diodes D3 and D4 on the diagram to complete the circuit
Date posted:
April 5, 2019
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Answers (1)
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The diagram below shows a simple cell:-
(Solved)
The diagram below shows a simple cell:-
(i) Name z and solution y
(ii) Name and explain the defect that occurs at plate z
(iii) Give one method of preventing the defect that occurs at the copper plate
Date posted:
April 5, 2019
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Answers (1)
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The diagram below shows a wrongly wired three pin plug.
(Solved)
The diagram below shows a wrongly wired three pin plug.
(i) Indicate in the diagram above the correct colors for the wiring
(ii) State the use of device marked X
Date posted:
April 5, 2019
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Answers (1)
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State the advantage of transmitting power at Alternating voltage.
(Solved)
State the advantage of transmitting power at Alternating voltage.
Date posted:
April 5, 2019
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Answers (1)
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State the advantage of transmitting power at Very high voltage
(Solved)
State the advantage of transmitting power at Very high voltage
Date posted:
April 5, 2019
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Answers (1)
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The figure below represents part of an electric cooker coil.
(Solved)
The figure below represents part of an electric cooker coil.
i) State why the part labeled W is coiled
(ii) State the property of material X that makes it suitable for its use
Date posted:
April 5, 2019
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Answers (1)
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State two ways of decreasing capacitance
(Solved)
State two ways of decreasing capacitance
Date posted:
April 5, 2019
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Answers (1)
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The figure below shows the wiring in a modern mains appliance
(Solved)
The figure below shows the wiring in a modern mains appliance
Identify the wires Y and Z
Date posted:
April 5, 2019
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Answers (1)
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Study the circuit below:
(Solved)
Study the circuit below:
Determine the current flowing in the circuit
Date posted:
April 5, 2019
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Answers (1)
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The diagram figure below shows a photocell connected in a circuit:-
(Solved)
The diagram figure below shows a photocell connected in a circuit:-
(i) Complete the diagram by indicating the correct polarities in the gap for current to flow in
the circuit.
(ii) State and explain the effect of using light of different wave lengths on the amount of
current flowing in the circuit given that the distance of the source of light remains the same
Date posted:
April 5, 2019
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Answers (1)
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The diagram below represents a cathode ray oscilloscope (CRO)
(Solved)
The diagram below represents a cathode ray oscilloscope (CRO)
i) Name the parts labeled A and B
ii) What are the functions of C and D?
iii) State how electrons are produced
iv) Give a reason why the tube is evacuated.
Date posted:
April 5, 2019
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Answers (1)
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State one reason why a C.R.O is a more accurate voltmeter than a moving coil voltmeter
(Solved)
State one reason why a C.R.O is a more accurate voltmeter than a moving coil voltmeter
Date posted:
April 5, 2019
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Answers (1)
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The graph below shows the relation between the stopping potential, Vs and the frequency of radiation when a certain surface is illuminated with light of...
(Solved)
The graph below shows the relation between the stopping potential, Vs and the frequency of radiation when a certain surface is illuminated with light of different frequencies
From the graph determine:-
(i) The threshold frequency
(ii) The value of plank’s constant (e = 1.6 x 10-19C)
(iii) The work function of the material
Date posted:
April 5, 2019
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Answers (1)
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Explain why a magnetic field is used in the TV deflection system instead of an electric field
(Solved)
Explain why a magnetic field is used in the TV deflection system instead of an electric field
Date posted:
April 5, 2019
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Answers (1)
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Name one factor that determines the velocity of photoelectrons produced on a metal surface
when light shine on it
(Solved)
Name one factor that determines the velocity of photoelectrons produced on a metal surface
when light shine on it
Date posted:
April 5, 2019
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Answers (1)