y =238-4(1) = 242
X = 84
sharon kalunda answered the question on April 5, 2019 at 14:11
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A radioactive element decays to 1/128 of its original activity after 49 days. Determine its
half –life
(Solved)
A radioactive element decays to 1/128 of its original activity after 49 days. Determine its
half –life
Date posted:
April 5, 2019
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Answers (1)
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Below is a nuclear reaction
(Solved)
Below is a nuclear reaction
i) Identify radiation K
ii) Determine the value of X and Y
Date posted:
April 5, 2019
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Answers (1)
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The figure shows the circuit of a modern X-ray tube
(Solved)
The figure shows the circuit of a modern X-ray tube
Name the part labeled C and state its function
Date posted:
April 5, 2019
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Answers (1)
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The diagram below shows simplified diagram of an x-ray tube,
(Solved)
The diagram below shows simplified diagram of an x-ray tube,
(a) Name the parts A, B, and C.
(b) What adjustments would be made to:
(i) Increase the penetrating power of the x-rays produced.
(ii) Increase the intensity of the rays produced.
(c) Name a suitable material for the part marked B and give a reason for your choice.
(d) Name a suitable material for the part marked C and sate its purpose.
(e) Why is it necessary to maintain a vacuum inside the tube?
Date posted:
April 5, 2019
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Answers (1)
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An x-ray tube is operating with an anode potential of 12Kv and a current of 10.0m.A:
(Solved)
An x-ray tube is operating with an anode potential of 12Kv and a current of 10.0m.A:
(i) Calculate the number of electrons hitting the anode per second
(ii) Determine the velocity with which the electrons strike the target
Date posted:
April 5, 2019
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Answers (1)
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The figure below shows an x-ray tube:
(Solved)
The figure below shows an x-ray tube:
(a) Indicate on the diagram the path of x-ray beam supplied by the tube
(b) Why is M set at angle of 45o relative to the electron beam?
(c) Name a suitable metal that can be used for part M and give a reason for your choice
(d) State how the following can be controlled:-
(i) Intensity
(ii) Penetrating power
(iii) The exposure to patients
Date posted:
April 5, 2019
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Answers (1)
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The table below shows the electromagnetic spectrum;
(Solved)
The table below shows the electromagnetic spectrum;
i) Identify A and B
ii) State one use for each
Date posted:
April 5, 2019
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Answers (1)
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An x-ray tube must be highly evaluated. Give a reason for this
(Solved)
An x-ray tube must be highly evaluated. Give a reason for this
Date posted:
April 5, 2019
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Answers (1)
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Give one use of X –rays in medicine
(Solved)
Give one use of X –rays in medicine
Date posted:
April 5, 2019
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Answers (1)
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The figure shows a cross- section of a bicycle dynamo. The wheel is connected by an axle
to a permanent cylindrical magnet and is rotated by...
(Solved)
The figure shows a cross- section of a bicycle dynamo. The wheel is connected by an axle
to a permanent cylindrical magnet and is rotated by the bicycle tyre
i) Explain why the bulb lights
ii) How can the bulb be made brighter
Date posted:
April 5, 2019
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Answers (1)
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The diagram below shows an arrangement of capacitors in a circuit
(Solved)
The diagram below shows an arrangement of capacitors in a circuit
Determine the total charge in the circuit
Date posted:
April 5, 2019
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Answers (1)
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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.
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
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Answers (1)
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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
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Answers (1)
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Figure below shows a diagram of an n – p – n transistor.
(Solved)
Figure below shows a diagram of an n – p – n transistor.
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
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Answers (1)
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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
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Answers (1)
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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
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Answers (1)
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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
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Answers (1)
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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.
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
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Answers (1)
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The figure below shows the set up for a simple cell.
(Solved)
The figure below shows the set up for a simple cell.
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
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Answers (1)
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Distinguish between Topping and Dopping
(Solved)
Distinguish between Topping and Dopping
Date posted:
April 5, 2019
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Answers (1)