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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
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- With the time base switched on; the following trace was obtained on the screen of a CRO as
shown in the figure below:(Solved)
With the time base switched on; the following trace was obtained on the screen of a CRO as
shown in the figure below:
Draw a circuit diagram that can be used to produce the wave above
Date posted: April 5, 2019. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- A household uses a 1.5Kw water heater for 2 hours a day for 30 days. If the cost of
electricity is shs.6.70 per Kwh, how much...(Solved)
A household uses a 1.5Kw water heater for 2 hours a day for 30 days. If the cost of
electricity is shs.6.70 per Kwh, how much will they pay for this consumption?
Date posted: April 5, 2019. Answers (1)
- 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. Answers (1)
- Aluminium wires are commonly used in power transmission than copper wires. Give two
advantages of aluminum as transmission lines(Solved)
Aluminium wires are commonly used in power transmission than copper wires. Give two
advantages of aluminum as transmission lines
Date posted: April 5, 2019. Answers (1)
- State the advantage of transmitting power at Alternating voltage.(Solved)
State the advantage of transmitting power at Alternating voltage.
Date posted: April 5, 2019. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- State two ways of decreasing capacitance(Solved)
State two ways of decreasing capacitance
Date posted: April 5, 2019. Answers (1)
- 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. Answers (1)
- Study the circuit below:(Solved)
Study the circuit below:
Determine the current flowing in the circuit
Date posted: April 5, 2019. Answers (1)
- You are provided with the following; a photo cell; a source of UV light, a rheostat,
a source of e.m.f, a millimeter, a voltmeter and connecting...(Solved)
You are provided with the following; a photo cell; a source of UV light, a rheostat,
a source of e.m.f, a millimeter, a voltmeter and connecting wires. Draw a circuit
diagram to show how photoelectric effect may be demonstrated in the laboratory
Date posted: April 5, 2019. Answers (1)
- A transformer with 4200 turns in the primary coil operates a 240V mains supply and gives an
output of 8.0V. Determine the number of turns in...(Solved)
A transformer with 4200 turns in the primary coil operates a 240V mains supply and gives an
output of 8.0V. Determine the number of turns in the secondary coil (assuming it is 10% efficient)
Date posted: April 5, 2019. Answers (1)
- Two fixed resistors one of 100 ohms and the other of unknown resistance are connected in parallel.
The combination is placed in a circuit and current...(Solved)
Two fixed resistors one of 100 ohms and the other of unknown resistance are connected in parallel.
The combination is placed in a circuit and current passing through the combination was
measured for various p.d. The graph in figure 10 below drawn to scale shows the results:-
(i) From the graph, calculate the total resistance of the combination
(ii) Determine the value of the unknown resistance
Date posted: April 5, 2019. Answers (1)