i) To be easily ionized by the radiation.
ii) Acts as a quenching agent
Absorbing kinetic energy of the positive ions
Kavungya answered the question on October 17, 2019 at 11:32
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An object 10cm high is placed 30cm in front of a concave mirror. The image is 45cm in front of the mirror. Find its magnification...
(Solved)
An object 10cm high is placed 30cm in front of a concave mirror. The image is 45cm in front of the mirror. Find its magnification and size of the image.
Date posted:
October 17, 2019
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Answers (1)
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In an attempt to make a magnet, a student used the double stroke method as shown below.
State the polarities at the ends A and B
(Solved)
In an attempt to make a magnet, a student used the double stroke method as shown below.
State the polarities at the ends A and B
Date posted:
October 17, 2019
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Answers (1)
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500g of water at 200C is mixed with 200g of water at 550C. Find the final temperature of the mixture.
(Solved)
500g of water at 200C is mixed with 200g of water at 550C. Find the final temperature of the mixture.
Date posted:
October 17, 2019
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Answers (1)
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A car moving initially at 10m/s decelerates at 2.5m/s2
Determine:
i)I) Its velocity after 1.5seconds.
II)The distance travelled in 1.5 seconds.
III)The time taken for the car to stop.
ii)Sketch...
(Solved)
A car moving initially at 10m/s decelerates at 2.5m/s2
Determine:
i)I) Its velocity after 1.5seconds.
II)The distance travelled in 1.5 seconds.
III)The time taken for the car to stop.
ii)Sketch the velocity – time graph for the motion of the car up to the time the car stopped.
iii)From the graph determine the distance the car travelled before stopping.
Date posted:
October 17, 2019
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Answers (1)
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The diagram below shows a six’s maximum/ minimum thermometer.
a)What is the thermometric liquid in this thermometer?
b)Why is it necessary for the vapour in bulb B...
(Solved)
The diagram below shows a six’s maximum/ minimum thermometer.
)What is the thermometric liquid in this thermometer?
b)Why is it necessary for the vapour in bulb B to be saturated?
c)Explain how the thermometer indicates maximum and minimum temperature.
d)Indicate on the diagram the two points where the reading of the temperature shown by the
thermometer can be made.
Date posted:
October 17, 2019
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Answers (1)
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Use the figure below to answer the questions that follow
i)What pressure is acting on point A?
ii)What is the value of pressure difference in the...
(Solved)
Use the figure below to answer the questions that follow
i)What pressure is acting on point A?
ii)What is the value of pressure difference in the instrument reading?
iii)If the atmospheric pressure is 760mm of mercury, what is the value of gas pressure?
Date posted:
October 17, 2019
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Answers (1)
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The figure below shows an incompressible fluid moving through a tube of varied cross- sectional area. If the area of the small tube is 0.05m2,...
(Solved)
The figure below shows an incompressible fluid moving through a tube of varied cross- sectional area. If the area of the small tube is 0.05m2, calculate the diameter of the large tube in cm.
Date posted:
October 17, 2019
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Answers (1)
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The figure below shows two light sheets of paper arranged as shown.
Explain the observation made when air is blown at the same speed and time...
(Solved)
The figure below shows two light sheets of paper arranged as shown.
Explain the observation made when air is blown at the same speed and time at points A and B.
Date posted:
October 17, 2019
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Answers (1)
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Distinguish between streamline and turbulent flow.
(Solved)
Distinguish between streamline and turbulent flow.
Date posted:
October 17, 2019
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Answers (1)
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A bullet of mass 20g moving with a velocity of 30m/s penetrates a sand bag and it’s brought to rest in 0.05 seconds. Find the...
(Solved)
A bullet of mass 20g moving with a velocity of 30m/s penetrates a sand bag and it’s brought to rest in 0.05 seconds. Find the average retarding force of the sand.
Date posted:
October 17, 2019
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Answers (1)
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A tightly fitted bottle cork will be easier to remove if the bottle is warmed. Explain this using kinetic and thermal property of matter.
(Solved)
A tightly fitted bottle cork will be easier to remove if the bottle is warmed.
Explain this using kinetic and thermal property of matter.
Date posted:
October 17, 2019
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Answers (1)
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State one way of increasing sensitivity of mercury in glass thermometer.
(Solved)
State one way of increasing sensitivity of mercury in glass thermometer.
Date posted:
October 17, 2019
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Answers (1)
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A mercury barometer reads 75cmHg at the base of Mt.Kenya. Assuming that the height of
the mountain is 1088m and the average density of air...
(Solved)
A mercury barometer reads 75cmHg at the base of Mt.Kenya. Assuming that the height of
the mountain is 1088m and the average density of air is 1.25kg/m3. What is the reading of the
barometer at the top of the mountain? (Take density of mercury is 13.6g/cm3.)
Date posted:
October 17, 2019
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Answers (1)
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Before using a vernier calipers to measure diameter of a steel ball, a student confirmed that it had a zero error of -0.03cm. The figure...
(Solved)
Before using a vernier calipers to measure diameter of a steel ball, a student confirmed that it had a zero error of -0.03cm. The figure below shows the vernier calipers scale when in use.
State the correct diameter of the steel ball.
Date posted:
October 17, 2019
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Answers (1)
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Figure below shows a solenoid with a ferromagnetic core connected to a battery E, ammeter A and rheostat R
On the figure indicate;
(i)The direction of current...
(Solved)
Figure below shows a solenoid with a ferromagnetic core connected to a battery E, ammeter A and rheostat R
On the figure indicate;
(i)The direction of current in the external circuit and around the coils.
(ii)The polarity of the resulting electromagnet
(iii)The direction of the magnetic field lines created around the solenoid
Date posted:
October 3, 2019
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Answers (1)
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The figure below shows a transparent water tank containing water. An electric lamp surrounded by a shield with a narrow slit of fixed at corner...
(Solved)
The figure below shows a transparent water tank containing water. An electric lamp surrounded by a shield with a narrow slit of fixed at corner A of the tank. A light ray from the slit shines on the water surface BC, at an angle of 48o as shown.
a)Determine the angle of refraction for the ray shown.
b)Complete the ray diagram to show the refracted ray.
c)Determine the angle of incidence for which the angle of refraction is 90o.
d)Calculate the speed of light in water.
Date posted:
October 3, 2019
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Answers (1)
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Explain why a 12V car battery is able to start the motor car engine while eight dry cells of 1.5 v each connected in series...
(Solved)
Explain why a 12V car battery is able to start the motor car engine while eight dry cells of 1.5 v each connected in series will not.
Date posted:
October 3, 2019
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Answers (1)
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The diagram below represents an X –ray tube. The anode is made up of copper metal and tungsten as the target.
(Solved)
The diagram below represents an X –ray tube. The anode is made up of copper metal and tungsten as the target.
a) What are the functions of parts A and B.
b) Explain how X-rays are produced from the tube
c) Why is tungsten used for the target in the tube?
d) How can the quality of X-rays produced be controlled in the tube?
e) How can the quantity of the X-rays be increased?
Date posted:
October 2, 2019
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Answers (1)
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The following results were obtained in a experiment to verify Hooke’s law when a spring was extended by hanging various loads on it.
(I) Complete...
(Solved)
The following results were obtained in a experiment to verify Hooke’s law when a spring was extended by hanging various loads on it.
(I) Complete the table for the extension e above.
(II) Plot a graph of load (y-axis) against extension
(III) From the graph determine the springs constant
(IV) Calculate the energy stored when the spring is stretched to 16 cm.
Date posted:
October 1, 2019
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Answers (1)
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A stone of mass 5g is released from a catapult. The catapult is stretched by 10cm. If the constant of elasticity is 100N/cm. Calculate;
(i)...
(Solved)
A stone of mass 5g is released from a catapult. The catapult is stretched by 10cm. If the constant of elasticity is 100N/cm. Calculate;
(i) The horizontal velocity with which the stone is released
(ii) Sketch a graph of horizontal velocity against time from the time the stone is released to when it reaches the ground.
Date posted:
October 1, 2019
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Answers (1)