Get premium membership and access questions with answers, video lessons as well as revision papers.
- convex lens forms an image four times the size of the object on a screen. If the distance between the object and the
screen is...(Solved)
A convex lens forms an image four times the size of the object on a screen. If the distance between the object and the
screen is 10cm.
Determine :
i) the image distance.
ii) focal length of the lens.
Date posted: May 29, 2019. Answers (1)
- The figure below show an X-ray tube.
b)i) Briefly explain how X-rays are produced.
ii) What adjustment should be made on the tube to produce hard...(Solved)
The figure below show an X-ray tube.
a)i) Briefly explain how X-rays are produced.
ii) What adjustment should be made on the tube to produce hard X-rays if initially it was producing soft X-rays.
b) What are the functions of the following on the cathode ray oscilloscope ?
i) X-plates.
ii) Grid.
Date posted: May 29, 2019. Answers (1)
- A radio station is transmitting at a frequency of 15MHz. Calculate the wavelength of the transmission.(Solved)
A radio station is transmitting at a frequency of 15MHz. Calculate the wavelength of the transmission.
Date posted: May 29, 2019. Answers (1)
- Arrange the electromagnetic wave below in ascending order of wavelength. visible light, infrared, ultraviolet, radio
waves, gamma rays, x-rays.(Solved)
Arrange the electromagnetic wave below in ascending order of wavelength. visible light, infrared, ultraviolet, radio
waves, gamma rays, x-rays.
Date posted: May 29, 2019. Answers (1)
- In a transformer, a voltage of 240V is to be stepped down to 24V. The primary current is found to be 1.5A while thesecondary current...(Solved)
In a transformer, a voltage of 240V is to be stepped down to 24V. The primary current is found to be 1.5A while the
secondary current is 14A. Calculate :
i) Power input
ii) Power output
iii) Power wasted
iv) Efficiency of the transformer
Date posted: May 29, 2019. Answers (1)
- The figure below shows one method of a.c rectification using four diodes, A, B, C, D.
Explain how the a.c rectification is achieved in the above...(Solved)
The figure below shows one method of a.c rectification using four diodes, A, B, C, D.
Explain how the a.c rectification is achieved in the above circuit.
Date posted: May 29, 2019. Answers (1)
- What is meant by the term “A.C rectification”.(Solved)
What is meant by the term “A.C rectification”.
Date posted: May 29, 2019. Answers (1)
- In the nuclear equation below, find a and b(Solved)
In the nuclear equation below, find a and b
Date posted: May 29, 2019. Answers (1)
- The figure below shows a Geiger Muller (GM) tube.
i) Name the part labelled A and B
ii) State one reason why halogen gas is used...(Solved)
The figure below shows a Geiger Muller (GM) tube.
i) Name the part labelled A and B
ii) State one reason why halogen gas is used in the GM tube.
Date posted: May 29, 2019. Answers (1)
- In an experiment to determine the half life of thoron 220, the results were plotted as shown.
From the graph, determine the half life of thoron...(Solved)
In an experiment to determine the half life of thoron 220, the results were plotted as shown.
From the graph, determine the half life of thoron 220.
Date posted: May 29, 2019. Answers (1)
- A certain radioactive material has half life of 20 minutes. Calculate the fraction of the original mass that would be
remaining after two hours.(Solved)
A certain radioactive material has half life of 20 minutes. Calculate the fraction of the original mass that would be
remaining after two hours.
Date posted: May 29, 2019. Answers (1)
- The figure below shows the deflection of radiation from a radioactive substance by an electric field.
Identify the radiations P, Q and R(Solved)
The figure below shows the deflection of radiation from a radioactive substance by an electric field.
Identify the radiations P, Q and R
Date posted: May 29, 2019. Answers (1)
- The figure below shows a circuit diagram for a photocell.i) Explain why the milliammeter shows a deflection when ultraviolet light is shone on the photocell.ii)...(Solved)
The figure below shows a circuit diagram for a photocell.
i) Explain why the milliammeter shows a deflection when ultraviolet light is shone on the photocell.
ii) Explain how the milliammeter reading is affected when the intensity of UV light is increased.
Date posted: May 29, 2019. Answers (1)
- a)The graph below shows the variation of stopping potential against frequency.
b) A certain metal has work function of 4.83eV. Calculate the maximum kinetic energy in...(Solved)
The graph below shows the variation of stopping potential against frequency.
From the graph, determine Plank’s constant.
b) A certain metal has work function of 4.83eV. Calculate the maximum kinetic energy in joules of the electrons
emitted when the metal is irradiated with ultraviolet light of frequency 1.9 x 1015Hz. (Use Planks constant obtained
above.)
Date posted: May 29, 2019. Answers (1)
- The figure below shows four capacitors connected to a battery of 12 volts.
Calculate :
i) effective capacitance.
ii) charge on the capacitor of 3.2
iii) p.d across the...(Solved)
The figure below shows four capacitors connected to a battery of 12 volts.
Calculate :
i) effective capacitance.
ii) charge on the capacitor of 3.2
iii) p.d across the capacitor of 5
iv) the energy stored by the capacitor of 2
Date posted: May 29, 2019. Answers (1)
- The figure shows a bar magnet FG being pushed into a coil connected to a centre zero galvanometer. The current induced in the coil is...(Solved)
The figure shows a bar magnet FG being pushed into a coil connected to a centre zero galvanometer. The current induced in the coil is shown.
State the polarity of F.
Date posted: May 29, 2019. Answers (1)
- State two differences between light waves and sound waves.(Solved)
State two differences between light waves and sound waves.
Date posted: May 29, 2019. Answers (1)
- The figure shows a transverse wave.
a) Calculate the frequency of the wave.
b) Sketch another wave on the same diagram that has double the frequency and...(Solved)
The figure shows a transverse wave.
a) Calculate the frequency of the wave.
b) Sketch another wave on the same diagram that has double the frequency and half the amplitude and label it
as m.
Date posted: May 29, 2019. Answers (1)
- The figure below shows a simple circuit breaker.
Explain briefly how it works.(Solved)
The figure below shows a simple circuit breaker.
Explain briefly how it works.
Date posted: May 29, 2019. Answers (1)
- One method of making a simple d.c motor more powerful is to wind the coil on a soft iron core. Explain how this
method increases the...(Solved)
One method of making a simple d.c motor more powerful is to wind the coil on a soft iron core. Explain how this
method increases the power of the motor.
Date posted: May 29, 2019. Answers (1)