- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- Arrange the following waves in order of increasing frequencies: microwaves, x-rays,
Infra-red, ultra-violet(Solved)
Arrange the following waves in order of increasing frequencies: microwaves, x-rays,
Infra-red, ultra-violet
Date posted: April 5, 2019. Answers (1)
- 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. Answers (1)
- State the factor that affects:-
(i) The intensity of X-rays
(ii) The strength of X-rays(Solved)
State the factor that affects:-
(i) The intensity of X-rays
(ii) The strength of X-rays
Date posted: April 5, 2019. Answers (1)
- Give one use of X –rays in medicine(Solved)
Give one use of X –rays in medicine
Date posted: April 5, 2019. Answers (1)
- 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. Answers (1)
- A transformer is designed as shown in the figure below. If the primary coil has 2400 turns and
the secondary has 200 turns calculate the p.d...(Solved)
A transformer is designed as shown in the figure below. If the primary coil has 2400 turns and
the secondary has 200 turns calculate the p.d across BC assuming there are no energy losses in
the transformer
Date posted: April 5, 2019. Answers (1)
- What would be observed in the diagram below when switch S is closed, B1 and B2 are
identical torch bulbs(Solved)
What would be observed in the diagram below when switch S is closed, B1 and B2 are
identical torch bulbs
Date posted: April 5, 2019. Answers (1)
- 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. Answers (1)
- 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. 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:-
(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.
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)