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- Derive an expression for obtaining the diameter, d of a molecule of oil(Solved)
An oil drop of volume V m3 introduced on the surface of water spreads to form patch whose area is Am2. Derive an expression for obtaining the diameter, d of a molecule of oil.
Date posted: February 7, 2017.
- State two environmental hazards that may occur when oil spills over a large surface area of the sea(Solved)
State two environmental hazards that may occur when oil spills over a large surface area of the sea.
Date posted: February 7, 2017.
- When a drop of oleic acid of known volume is dropped on the surface of water in a large trough, it spreads out to form a large circular patch(Solved)
When a drop of oleic acid of known volume is dropped on the surface of water in a large trough, it spreads out to form a large circular patch. State one assumption made when the size of the molecule of oleic acid is estimated by determining the area of the patch.
Date posted: February 7, 2017.
- In an experiment to estimate the diameter of an oil molecule, an oil drop of diameter 0.05 cm spreads over a circular patch whose diameter is 20 cm(Solved)
In an experiment to estimate the diameter of an oil molecule, an oil drop of diameter 0.05 cm spreads over a circular patch whose diameter is 20 cm.
Determine i) the volume of the oil drop
ii) The area of the patch covered by the oil
iii) The diameter of the oil molecule
Date posted: February 7, 2017.
- State the assumption made when calculating the size of a molecule in the oil drop experiment(Solved)
State the assumption made when calculating the size of a molecule in the oil drop experiment
Date posted: February 7, 2017.
- Name the instrument that would be most suitable for measuring the thickness of one sheet of this question paper.(Solved)
Name the instrument that would be most suitable for measuring the thickness of one sheet of this question paper.
Date posted: February 7, 2017.
- State the reason why the magnetic field strength of a magnet is greatest at the poles(Solved)
State the reason why the magnetic field strength of a magnet is greatest at the poles.
Date posted: February 7, 2017.
- One method of producing a weak magnet is to hold a steel rod in the North South direction and the hammer is continuously for some time(Solved)
One method of producing a weak magnet is to hold a steel rod in the North South direction and the hammer is continuously for some time. Using the domain theory of magnetism explain how this method works.
Date posted: February 7, 2017.
- An un-magnetized steel rod is clamped facing North-South direction and then hammered repeatedly for some time. When tested, it is found to be magnetized(Solved)
An un-magnetized steel rod is clamped facing North-South direction and then hammered repeatedly for some time. When tested, it is found to be magnetized. Explain this observation
Date posted: February 7, 2017.
- How can it be shown that the strength of a magnet is concentrated at the poles(Solved)
How can it be shown that the strength of a magnet is concentrated at the poles
Date posted: February 7, 2017.
- Explain how hammering demagnetizes a magnet(Solved)
Explain how hammering demagnetizes a magnet
Date posted: February 7, 2017.
- Distinguish between soft and hard magnetic materials(Solved)
Distinguish between soft and hard magnetic materials
Date posted: February 7, 2017.
- Given a bar magnet, an iron bar and a string
i) Describe a simple experiment to distinguish between the magnet and the iron bar
(ii) State...(Solved)
Given a bar magnet, an iron bar and a string
i) Describe a simple experiment to distinguish between the magnet and the iron bar
(ii) State with reasons the observations that would be made in the experiment.
Date posted: February 7, 2017.
- Give reason why attraction in magnetism is not regarded as reliable method of testing for polarity(Solved)
Give reason why attraction in magnetism is not regarded as reliable method of testing for polarity
Date posted: February 7, 2017.
- State the reason for topping up a lead-acid accumulator with distilled water(Solved)
State the reason for topping up a lead-acid accumulator with distilled water.
Date posted: February 7, 2017.
- State the purpose of manganese dioxide in a dry cell(Solved)
State the purpose of manganese dioxide in a dry cell.
Date posted: February 7, 2017.
- State one advantage of a lead-acid accumulator over a nickel-iron(NiFe) accumulator(Solved)
State one advantage of a lead-acid accumulator over a nickel-iron(NiFe) accumulator.
Date posted: February 7, 2017.
- Explain how polarization reduces current in a simple cell(Solved)
Explain how polarization reduces current in a simple cell
Date posted: February 7, 2017.
- State one advantage of alkaline accumulator over a lead-acid accumulator(Solved)
State one advantage of alkaline accumulator over a lead-acid accumulator
Date posted: February 7, 2017.
- A car battery requires topping up with distilled water occasionally. Explain why this is necessary and why distilled water is used(Solved)
A car battery requires topping up with distilled water occasionally. Explain why this is necessary and why distilled water is used
Date posted: February 7, 2017.
- A current of 0.5 A flows in a circuit. Determine the quantity of charge that crosses a point in 4 minutes(Solved)
A current of 0.5 A flows in a circuit. Determine the quantity of charge that crosses a point in 4 minutes
Date posted: February 7, 2017.
- State two advantages of an alkaline battery over a lead acid battery(Solved)
State two advantages of an alkaline battery over a lead acid battery.
Date posted: February 7, 2017.
- It is observed that when a charged body is brought near the cap of a positively charged electroscope, the divergence of leaf increases(Solved)
It is observed that when a charged body is brought near the cap of a positively charged electroscope, the divergence of leaf increases. State the type of charge on the body
Date posted: February 7, 2017.
- State two uses of a charged gold leaf electroscope(Solved)
State two uses of a charged gold leaf electroscope.
Date posted: February 7, 2017.
- A positively charged sphere is suspended by an insulating thread. A negatively charged conductor is suspended near it(Solved)
A positively charged sphere is suspended by an insulating thread. A negatively charged conductor is suspended near it. The conductor is first attracted, after touching the sphere it is repelled. Explain this observation
Date posted: February 7, 2017.
- A conductor is slowly brought near the cap of a positively charged electroscope. The leaf first collapses and then diverges(Solved)
A conductor is slowly brought near the cap of a positively charged electroscope. The leaf first collapses and then diverges. State the charge on the conductor
Date posted: February 7, 2017.
- A leaf electroscope A is charged and placed on the bench. Another uncharged leaf electroscope B is placed on the same bench and moved close to A until the caps touch(Solved)
A leaf electroscope A is charged and placed on the bench. Another uncharged leaf electroscope B is placed on the same bench and moved close to A until the caps touch. State and explain what is observed on the leaves of A and B.
Date posted: February 7, 2017.
- A positively charged rod is brought near the cap of a leaf electroscope. The cap is the earthed momentarily by touching with the finger(Solved)
A positively charged rod is brought near the cap of a leaf electroscope. The cap is the earthed momentarily by touching with the finger. Finally the rod is withdrawn. The electroscope is found to be negatively charged. Explain how this charge is acquired.
Date posted: February 7, 2017.
- 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.
- State the law of electrostatic charges(Solved)
State the law of electrostatic charges
Date posted: February 7, 2017.