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- In an X-ray tube, the electrons are accelerated by a p.d of 24000V. Assuming that 2% of energy produced is converted
to X-rays. Determine the :
i)...(Solved)
In an X-ray tube, the electrons are accelerated by a p.d of 24000V. Assuming that 2% of energy produced is converted
to X-rays. Determine the :
i) energy of the X-rays produced.
ii) frequency of X-rays produced (take planks constant h = 6.6 x 10-34Js and charge on an electron e= 1.6 x 10-19C)
Date posted: May 30, 2019. Answers (1)
- The figure below shows the circuits close to each other.
When the switch is closed, the galvanometer shows a reading and then returns to zero.
i) Explain...(Solved)
The figure below shows the circuits close to each other.
When the switch is closed, the galvanometer shows a reading and then returns to zero.
i) Explain the observation
ii) Give one adjustment that can be done to the arrangement so that
I. the galvanometer gives a bigger deflection in the same direction.
II. the galvanometer deflects in opposite direction when the switch is closed.
Date posted: May 30, 2019. Answers (1)
- The figure below shows an electrical circuit with three capacitors A, B and C.
Determine :
i) the current flowing in the system.
ii) the total...(Solved)
The figure below shows an electrical circuit with three capacitors A, B and C.
Determine :
i) the current flowing in the system.
ii) the total capacitance of the capacitors.
iii) the total charge stored in the capacitors.
iv) The time needed to fully charge the capacitors.
Date posted: May 30, 2019. Answers (1)
- The figure below shows two parallel plate capacitors connected to a battery. Initially the switch S is open.
The switch is now closed and left for...(Solved)
The figure below shows two parallel plate capacitors connected to a battery. Initially the switch S is open.
The switch is now closed and left for a few seconds.
i) In the space below sketch a graph of current reading with time from time the switch is closed.
ii) Determine the reading of V after a long time.
iii) How does the capacitance of the plates change when the plates are moved further apart.
Date posted: May 30, 2019. Answers (1)
- The figure below shows an object and its image on a concave mirror. It is drawn to a scale of 1 : 10
Using a ray...(Solved)
The figure below shows an object and its image on a concave mirror. It is drawn to a scale of 1 : 10
Using a ray from the object, determine
a) the position of the principal focus.
b) the focal length of the mirror
Date posted: May 30, 2019. Answers (1)
- Uranium U 234 decays to Polonium P 218 by emitting alpha particles. Determine the number of alpha particles emitted.(Solved)
Uranium U 234 decays to Polonium P 218 by emitting alpha particles. Determine the number of alpha particles emitted.
Date posted: May 30, 2019. Answers (1)
- Name one electromagnetic wave whose energy is higher than that of visible light.(Solved)
Name one electromagnetic wave whose energy is higher than that of visible light.
Date posted: May 30, 2019. Answers (1)
- The table below shows some electrical appliances to be used in a house. The electrical rating for each appliance is shown.
a) Determine the resistance of...(Solved)
The table below shows some electrical appliances to be used in a house. The electrical rating for each appliance is shown.
a) Determine the resistance of the coil of the TV set.
b) Determine the appropriate current of each fuse used in the house.
Date posted: May 30, 2019. Answers (1)
- The figure below shows a tuning fork producing waves. The wave fronts are as in the diagram.
If the speed of sound in air is 330m/s....(Solved)
The figure below shows a tuning fork producing waves. The wave fronts are as in the diagram.
If the speed of sound in air is 330m/s. Determine the value of d.
Date posted: May 30, 2019. Answers (1)
- It is advisable to top up acid level of an accumulator with distilled water and not acid. Give a reason for this.(Solved)
It is advisable to top up acid level of an accumulator with distilled water and not acid. Give a reason for this.
Date posted: May 30, 2019. Answers (1)
- The figure below shows three resistors and a p.d of 24V across the resistors.Determine the reading of the voltmeter V.(Solved)
The figure below shows three resistors and a p.d of 24V across the resistors.Determine the reading of the voltmeter V.
Date posted: May 30, 2019. Answers (1)
- For an echo to be heard, the minimum distance between the obstacle and the observer must be 17m.If the minimum time for hearing an echo...(Solved)
For an echo to be heard, the minimum distance between the obstacle and the observer must be 17m.If the minimum time for hearing an echo is 0.1 seconds. Determine the speed of sound in air.
Date posted: May 30, 2019. Answers (1)
- The figure below shows plane waves incident on a plane reflector inclined at 60oC to the horizontal.
Complete the diagram to show reflected waves.(Solved)
The figure below shows plane waves incident on a plane reflector inclined at 60oC to the horizontal.
Complete the diagram to show reflected waves.
Date posted: May 30, 2019. Answers (1)
- The figure below shows a plane mirror and the word PHYSICS written on its front.
On the same diagram, write down the appearance of the word...(Solved)
The figure below shows a plane mirror and the word PHYSICS written on its front.
On the same diagram, write down the appearance of the word after reflection on the mirror.
Date posted: May 30, 2019. Answers (1)
- The figure below shows a balloon held under water in a container by a string tied to the bottom of the container.
Explain the change in...(Solved)
The figure below shows a balloon held under water in a container by a string tied to the bottom of the container.
Explain the change in the value of the tension T, as the water gets heated.
Date posted: May 30, 2019. Answers (1)
- The figure below shows a turn table on which a mass of 50g is placed 10cm from the centre.
Frictional force between the 50g mass and...(Solved)
The figure below shows a turn table on which a mass of 50g is placed 10cm from the centre.
Frictional force between the 50g mass and the turn table is 0.4N. When the turntable is made to rotate with angular velocity of
ὦ rads-1 the mass must starts to slide off.
i) Determine the :
I. angular velocity ὦ,
II. time taken to make one complete revolution
ii) On the figure draw a path that would be taken by the 50g mass if the turntable suddenly came to a stop.
Date posted: May 30, 2019. Answers (1)
- The figure below shows a cylinder of mass 300g.
Kerosene of density 800kgm-3 is poured into the cylinder and the cylinder is made to float on...(Solved)
The figure below shows a cylinder of mass 300g.
Kerosene of density 800kgm-3 is poured into the cylinder and the cylinder is made to float on liquid L. It is found that the cylinder sinks with half its height sunk in liquid L. Kerosene rises in the cylinder to a height of 5cm.
Determine :
a) the weight of the empty cylinder.
b) the upthrust experienced on the cylinder and its contents.
c) the density of liquid L
Date posted: May 30, 2019. Answers (1)
- Sketch the graph of density of water against temperature upto 10oC.(Solved)
Sketch the graph of density of water against temperature upto 10oC.
Date posted: May 30, 2019. Answers (1)
- The figure below shows variation of volume of water and temperature as water is heated from 0oC to 40oC
State the value of P.(Solved)
The figure below shows variation of volume of water and temperature as water is heated from 0oC to 40oC
State the value of P.
Date posted: May 30, 2019. Answers (1)
- Apart from the definitions, distinguish between temperature and heat.(Solved)
Apart from the definitions, distinguish between temperature and heat.
Date posted: May 30, 2019. Answers (1)