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- Figure shows a circuit where a battery of emf 4.5V, switches A and B, two capacitors.C1= 0.3 µF and C2 = 0.5 µF and a...(Solved)
Figure shows a circuit where a battery of emf 4.5V, switches A and B, two capacitors.C1= 0.3 μF and C2 = 0.5 μF and a voltmeter are connected.
![p5420191549.png](/questions/uploads/p5420191549.png)
a) Determine the charge on C1 when switch A is closed and switch B is open
b) What is the effective capacitance CT when both switches A and B are closed?
Date posted: April 5, 2019. Answers (1)
- In an attempt to establish the relationship between current through a junction diode and the p.d
across it, a student connected a diode to an e.m.f...(Solved)
In an attempt to establish the relationship between current through a junction diode and the p.d
across it, a student connected a diode to an e.m.f source as in figure below:-
![p5420191538.png](/questions/uploads/p5420191538.png)
(a) State whether the diode is forward biased or reverse biased
(b) Briefly describe how she obtained her readings
Date posted: April 5, 2019. Answers (1)
- State the purpose of introducing an impurity in a semi conductor.(Solved)
State the purpose of introducing an impurity in a semi conductor.
Date posted: April 5, 2019. Answers (1)
- Figure below shows a diagram of an n – p – n transistor.(Solved)
Figure below shows a diagram of an n – p – n transistor.
![p5420191520.png](/questions/uploads/p5420191520.png)
Complete the diagram by showing the connections of two batteries suitable for biasing the
transistor in the common- emitter mode.
Date posted: April 5, 2019. Answers (1)
- Three identical bulbs are connected in series with a battery of dry cells. At first the bulbs
shine brightly but gradually become dimmer. Using the same...(Solved)
Three identical bulbs are connected in series with a battery of dry cells. At first the bulbs
shine brightly but gradually become dimmer. Using the same cells, explain how you
would increase the brilliance of the bulbs
Date posted: April 5, 2019. Answers (1)
- A girl opened up a used up dry cell and found the following:
i) The zinc casing was ‘eaten away’
ii) The cell was watery(Solved)
A girl opened up a used up dry cell and found the following:
i) The zinc casing was ‘eaten away’
ii) The cell was watery
Name the cell defect
Date posted: April 5, 2019. Answers (1)
- State one reason why colour televisions have a higher power rating than black and white
televisions(Solved)
State one reason why colour televisions have a higher power rating than black and white
televisions
Date posted: April 5, 2019. Answers (1)
- The figure shows a simple cell made of copper and zinc electrodes dipped in dilute
sulphuric acid(Solved)
The figure shows a simple cell made of copper and zinc electrodes dipped in dilute
sulphuric acid.
![p5420191459.png](/questions/uploads/p5420191459.png)
a) Identify the cathode
b) If a voltmeter is connected across the rods the reading is observed to reduce with time.
State two causes of this observation
Date posted: April 5, 2019. Answers (1)
- The figure below shows the set up for a simple cell.(Solved)
The figure below shows the set up for a simple cell.
![p5420191407.png](/questions/uploads/p5420191407.png)
a) Name the Electrode A and the solution B
b) State two reasons why the bulb goes off after a short time
Date posted: April 5, 2019. Answers (1)
- Distinguish between Topping and Dopping(Solved)
Distinguish between Topping and Dopping
Date posted: April 5, 2019. Answers (1)
- 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.
![p5420191355.png](/questions/uploads/p5420191355.png)
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:-
![p5420191343.png](/questions/uploads/p5420191343.png)
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:
![p5420191338.png](/questions/uploads/p5420191338.png)
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
![p5420191330.png](/questions/uploads/p5420191330.png)
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:-
![p5420191326.png](/questions/uploads/p5420191326.png)
(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.
![p5420191318.png](/questions/uploads/p5420191318.png)
(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)