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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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(a) An experiment was performed in the laboratory in the sequence described
I. Brought a positively charged plastic ruler near to the cap of an uncharged...
(Solved)
(a) An experiment was performed in the laboratory in the sequence described
I. Brought a positively charged plastic ruler near to the cap of an uncharged leaf electroscope
II. Touched the cap momentarily with the finger
III. Removed the ruler
Draw diagram to show charge distribution on the cap and leaf of the electroscope and the position of the leaf after each of the above procedure.
(b) What will be the effect observed if the ruler is removed before removing the finger?
(c) In a separate experiment, the charged plastic ruler was allowed to touch the cap of electroscope. State giving a reason whether or not there will be any difference in the results obtained in (a) above
(d) In a nylon manufacturing factory heavy rubber units were put under the spinning machines which were made of metal to absorb the noise. The following effects were observed
A. Workers sometimes received electric shock when there was no leakage of charge from the main cable.
B. Small pieces of nylon stuck to the thread but whenever the room was moist this did not occur
(i) State and explain the reasons for the observation in A and B above.
(ii) How would the effect in (d) A be corrected
Date posted:
October 3, 2019
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Answers (1)
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Figure below shows two bar magnets placed with the north poles close together
Sketch the magnetic field pattern between the two north poles.
(Solved)
Figure below shows two bar magnets placed with the north poles close together
Sketch the magnetic field pattern between the two north poles.
Date posted:
October 3, 2019
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Answers (1)
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A soldier standing 110m form a wall blows a whistle and hears an echo sometimes later. If the speed of sound in air is 33om/s,...
(Solved)
A soldier standing 110m form a wall blows a whistle and hears an echo sometimes later. If the speed of sound in air is 33om/s, how long does it take the soldier to hear the echo of the whistle?
Date posted:
October 3, 2019
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Answers (1)
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Figure below shows a bulb connected across a 6v supply through a resistance wire XY of length 25m
Compare and explain the brightness of the bulb...
(Solved)
Figure below shows a bulb connected across a 6v supply through a resistance wire XY of length 25m
Compare and explain the brightness of the bulb if the wire was replaced by one of same material and same diameter but 50cm long.
Date posted:
October 3, 2019
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Answers (1)
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Figure below shows a coil of insulated wire wound on a horse shoe soft iron core AB and connected to a power supplyName the polarity...
(Solved)
Figure below shows a coil of insulated wire wound on a horse shoe soft iron core AB and connected to a power supply
Name the polarity at;
A
B
Date posted:
October 3, 2019
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Answers (1)
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An object is placed 20cm in front of a concave mirror of focal length 10cm and another identical object is place 20cm infront of a...
(Solved)
An object is placed 20cm in front of a concave mirror of focal length 10cm and another identical object is place 20cm infront of a plane mirror
(i) Give one similarity of the image formed.
(ii) Give one difference between the image formed.
Date posted:
October 3, 2019
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Answers (1)
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In figure below power dissipated by the 16? resistor is 8w, what is the power dissipated in 200?
(Solved)
In figure below power dissipated by the 16Ω resistor is 8w, what is the power dissipated in 200Ω
Date posted:
October 3, 2019
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Answers (1)
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In an experiment to determine the half-life of the radioactive element,the following data was obtained.
(Solved)
In an experiment to determine the half-life of the radioactive element,the following data was obtained.
(i) Plot a decay curve for the element
(ii) Estimate from your graph the half-life of the element
Date posted:
October 2, 2019
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Answers (1)
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Use a suitable equation to show this decay
(Solved)
Radon nuclide 
decays to form polonium by emitting an alpha- particle use a suitable equation to show this decay
Date posted:
October 2, 2019
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Answers (1)
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Define background count
(Solved)
Define background count
Date posted:
October 2, 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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Determine the amount of current passing through the 2O resistor shown in the figure below
(Solved)
Determine the amount of current passing through the 2Ω resistor shown in the figure below
Date posted:
October 2, 2019
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Answers (1)
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The figure below shows two ways of biasing a P-N junction
(Solved)
The figure below shows two ways of biasing a P-N junction
(i) In which circuit will current flow?
(ii) Explain your answer in (i) above.
Date posted:
October 2, 2019
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Answers (1)
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The energy of a radiation is 3.8 x10-14 J.
(Solved)
The energy of a radiation is 3.8 x10-14 J. Determine the wavelength of the radiation
( h = 6.63x10-34JS,C=3.0 x 108m/s)
Date posted:
October 2, 2019
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Answers (1)
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Arrange the following radiations in order of increasing wavelength
(Solved)
Arrange the following radiations in order of increasing wavelength; Ultra-violet, Microwaves, Blue light, Yellow light
Date posted:
October 2, 2019
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Answers (1)
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Figure below shows an object at the bottom of a water container. Draw rays on the diagram to show the object as viewed from above.
(Solved)
Figure below shows an object at the bottom of a water container. Draw rays on the diagram to show the object as viewed from above.
Date posted:
October 1, 2019
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Answers (1)
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A girl looks into a plane mirror 3 m in front of her and sees the image of the wall which is 2.5 m behind her. What...
(Solved)
A girl looks into a plane mirror 3 m in front of her and sees the image of the wall which is 2.5 m behind her. What is the difference between the girl’s eyes and the image of the wall?
Date posted:
October 1, 2019
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Answers (1)
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It is observed that when a magnet breaks up into two, each of the pieces retains the characteristics of the original magnet. Explain
(Solved)
It is observed that when a magnet breaks up into two, each of the pieces retains the characteristics of the original magnet. Explain
Date posted:
October 1, 2019
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Answers (1)
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The figure below shows a bimetallic strip made of copper and iron at room temperature
If copper expands more than iron. Identify A and B if...
(Solved)
The figure below shows a bimetallic strip made of copper and iron at room temperature
If copper expands more than iron. Identify A and B if the bimetallic strip is placed in a refrigerator whose temperature is -700c.
Date posted:
October 1, 2019
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Answers (1)