The positive rod attracts the negative charge to the cap and repels the positive charge to the leaf. On earthing, the positive charge is neutralized and when the rod is withdrawn the negative charge on the cap repels each other and redistributes making the electroscope negatively charged
johnmulu answered the question on February 7, 2017 at 07:18
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A highly negatively charged rod is gradually brought close to the cap of a positively charged electroscope
(Solved)
A highly negatively charged rod is gradually brought close to the cap of a positively charged electroscope. It is observed that the leaf collapses initially and then diverges. Explain the observation.
Date posted:
February 7, 2017
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Answers (1)
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In certain pinhole camera, the screen is 10cm from the pinhole. When the camera is placed 6 m away from a tree, a sharp image of the tree 16 cm high
(Solved)
In certain pinhole camera, the screen is 10cm from the pinhole. When the camera is placed 6 m away from a tree, a sharp image of the tree 16 cm high is formed on the screen. Determine the height of the tree
Date posted:
February 7, 2017
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Answers (1)
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In a vacuum flask the walls enclosing the vacuum are silvered on the inside. State the reason for this
(Solved)
In a vacuum flask the walls enclosing the vacuum are silvered on the inside. State the reason for this
Date posted:
February 6, 2017
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Answers (1)
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A wooden bench and a metal bench are both left in the sun for a long time. Explain why the metal bench feels hotter to touch
(Solved)
A wooden bench and a metal bench are both left in the sun for a long time. Explain why the metal bench feels hotter to touch.
Date posted:
February 6, 2017
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Answers (1)
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State two variables that must be controlled in an experiment for comparing the thermal conductivities of different metal rods of the same diameter
(Solved)
State two variables that must be controlled in an experiment for comparing the thermal conductivities of different metal rods of the same diameter.
Date posted:
February 6, 2017
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Answers (1)
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When a liquid is heated in a glass flask, its level at first falls then rises. Explain this observation
(Solved)
When a liquid is heated in a glass flask, its level at first falls then rises. Explain this observation.
Date posted:
February 6, 2017
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Answers (1)
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Clinical thermometer has a constriction in the bore just above the bulb. State the use of this constriction
(Solved)
Clinical thermometer has a constriction in the bore just above the bulb. State the use of this constriction.
Date posted:
February 6, 2017
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Answers (1)
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Explain why a glass container with thick walls is more likely to crack than one with a thin wall when a very hot liquid is poured into it.
(Solved)
Explain why a glass container with thick walls is more likely to crack than one with a thin wall when a very hot liquid is poured into it.
Date posted:
February 6, 2017
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Answers (1)
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Give a reason why a concrete beam reinforced with steel does not crack when subjected to changes in temperature
(Solved)
Give a reason why a concrete beam reinforced with steel does not crack when subjected to changes in temperature.
Date posted:
February 6, 2017
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Answers (1)
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State why it is easier to separate water into drops than to separate a solid into smaller pieces
(Solved)
State why it is easier to separate water into drops than to separate a solid into smaller pieces
Date posted:
February 6, 2017
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Answers (1)
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Two identical beakers A and B containing equal volumes of water are placed on a bench. The water in A is cold while in B it is warm
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Two identical beakers A and B containing equal volumes of water are placed on a bench. The water in A is cold while in B it is warm. Identical pieces of potassium permanganate are placed gently at the bottom of each beaker inside the water. It is observed that the spread of colour in B is faster than in A. Explain this observation
Date posted:
February 6, 2017
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Answers (1)
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Distinguish between solid and liquid states of matter in terms of intermolecular forces
(Solved)
Distinguish between solid and liquid states of matter in terms of intermolecular forces.
Date posted:
February 6, 2017
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Answers (1)
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Two identical tubes A and B held horizontally contain air and water respectively. A small quantity of coloured gas is introduced at one end of A
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Two identical tubes A and B held horizontally contain air and water respectively. A small quantity of coloured gas is introduced at one end of A while a small quantity of coloured water is introduced at one end of B. State with reason the tube in which the colour will reach the other end faster.
Date posted:
February 6, 2017
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Answers (1)
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Explain the cause of random motion of smoke particles as observed in Brownian motion experiment using a smoke cell
(Solved)
Explain the cause of random motion of smoke particles as observed in Brownian motion experiment using a smoke cell.
Date posted:
February 6, 2017
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Answers (1)
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A student wearing sharp pointed heeled shoes is likely to damage a soft wooden floor
(Solved)
A student wearing sharp pointed heeled shoes is likely to damage a soft wooden floor. Explain
Date posted:
February 6, 2017
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Answers (1)
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In an experiment to demonstrate atmospheric pressure, a plastic bottle is partially filled with hot water and the bottle is then tightly corked
(Solved)
In an experiment to demonstrate atmospheric pressure, a plastic bottle is partially filled with hot water and the bottle is then tightly corked. After some time the bottle starts to get deformed.
i) State the purpose of the hot water
ii) State the reason why the bottle gets deformed
iii) Explain your answer in (ii)
Date posted:
February 6, 2017
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Answers (1)
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When a bicycle pump was sealed at the nozzle and the handle slowly pushed towards the nozzle, the pressure of the air inside increased
(Solved)
When a bicycle pump was sealed at the nozzle and the handle slowly pushed towards the nozzle, the pressure of the air inside increased. Explain this observation.
Date posted:
February 6, 2017
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Answers (1)
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Some water in a tin can was boiled for some time. The tin can was then sealed and cooled. After some time it collapsed
(Solved)
Some water in a tin can was boiled for some time. The tin can was then sealed and cooled. After some time it collapsed. Explain this observation
Date posted:
February 6, 2017
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Answers (1)
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The total weight of a car with passengers is 25, 000 N. The area of contact of each of the four tyres with the ground is 0.025m2
(Solved)
The total weight of a car with passengers is 25, 000 N. The area of contact of each of the four tyres with the ground is 0.025m2. Determine the minimum car tyre pressure
Date posted:
February 6, 2017
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Answers (1)
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State one advantage of fitting wide tyre on a vehicle that moves on earth roads
(Solved)
State one advantage of fitting wide tyre on a vehicle that moves on earth roads.
Date posted:
February 6, 2017
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Answers (1)