Gamma rays;
sharon kalunda answered the question on May 31, 2019 at 10:51
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An electric heater is rated 1kW, 240V. If the element is connected to 240V mains supply for 10 minutes, determine the amount of heat dissipated.
(Solved)
An electric heater is rated 1kW, 240V. If the element is connected to 240V mains supply for 10 minutes, determine the amount of heat dissipated.
Date posted:
May 31, 2019
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Answers (1)
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The figure below shows a circuit diagram. The emf of the cell is 1.5V. When the switch is closed, the voltmeter reads 1.3V and the
ammeter...
(Solved)
The figure below shows a circuit diagram. The emf of the cell is 1.5V. When the switch is closed, the voltmeter reads 1.3V and the
ammeter reads 0.8A.

Determine the internal resistance of the cell.
Date posted:
May 31, 2019
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Answers (1)
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The figure shows a ray of light travelling through a vacuum enters liquid X at an angle of 50°, travels through and emerges in
glass.
Determine angle...
(Solved)
The figure shows a ray of light travelling through a vacuum enters liquid X at an angle of 50°, travels through and emerges in
glass.

Determine angle Y.
Date posted:
May 31, 2019
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Answers (1)
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Identify the magnetic poles A, B, C and D in the diagram below.
(Solved)
Identify the magnetic poles A, B, C and D in the diagram below.

Date posted:
May 31, 2019
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Answers (1)
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A person claps his hands at approximately 0.5s intervals in front of a wall 90m away. He notices that each echo produced by the wall...
(Solved)
A person claps his hands at approximately 0.5s intervals in front of a wall 90m away. He notices that each echo produced by the wall coincides with the next clap.
i) Calculate the approximate speed of sound
ii) If the results obtained above were used as a basis for an experimental method to determine the speed of sound, what procedure should be adopted to obtain high accuracy in the timing part of the experiment?
Date posted:
May 31, 2019
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Answers (1)
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Give one property of sound waves
(Solved)
Give one property of sound waves
Date posted:
May 31, 2019
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Answers (1)
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The figure below shows a ray of light incident on a plane mirror.The mirror is rotated through 10° clockwise about point O in an axis...
(Solved)
The figure below shows a ray of light incident on a plane mirror.

The mirror is rotated through 10° clockwise about point O in an axis perpendicular to plane mirror. Determine the angle between the incident ray and the new reflected ray.
Date posted:
May 31, 2019
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Answers (1)
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Define power of a lens and give its units
(Solved)
Define power of a lens and give its units
Date posted:
May 31, 2019
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Answers (1)
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Suppose that an object is attached to a spring balance on the Earth's surface and Earth's speed of rotation is gradually increased. What effect, if...
(Solved)
Suppose that an object is attached to a spring balance on the Earth's surface and Earth's speed of rotation is gradually increased. What effect, if any, will this have on.
i) the gravitational attraction between the object and the Earth.
ii) the reading of the spring balance.
Date posted:
May 31, 2019
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Answers (1)
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Describe the changes that can be observed during discharging process of a lead –acid accumulator
(Solved)
Describe the changes that can be observed during discharging process of a lead –acid accumulator
Date posted:
May 31, 2019
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Answers (1)
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An object put on a beam balance gives the same reading no matter where it is on the Earth's surface, but if it is on...
(Solved)
An object put on a beam balance gives the same reading no matter where it is on the Earth's surface, but if it is on a very
sensitive spring balance, the reading varies from place to place. Explain why this is so.
Date posted:
May 31, 2019
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Answers (1)
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Give a reason why the driver of the car has to move through the same bend at a lower speed during a rainy day.
(Solved)
Give a reason why the driver of the car has to move through the same bend at a lower speed during a rainy day.
Date posted:
May 31, 2019
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Answers (1)
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The figure shows a defective beam balance with unequal arms. The beam balances with no masses in the pans X and Y.
i)Suggest why this could...
(Solved)
The figure shows a defective beam balance with unequal arms. The beam balances with no masses in the pans X and Y.

i)Suggest why this could be possible.
ii) If a mass of 300g is placed in pan Y, Calculate the mass which must be placed in pan X to restore the balance.
Date posted:
May 31, 2019
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Answers (1)
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Calculate the maximum speed at which the car can go round the bend without skidding if the coefficient of friction between the tyres and the...
(Solved)
Calculate the maximum speed at which the car can go round the bend without skidding if the coefficient of friction between the tyres and the ground is 0.5.
Date posted:
May 31, 2019
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Answers (1)
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A car goes round a flat circular bend whose radius is 100m at a constant speed of 30m/s. Calculate its acceleration
(Solved)
A car goes round a flat circular bend whose radius is 100m at a constant speed of 30m/s. Calculate its acceleration
Date posted:
May 31, 2019
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Answers (1)
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The figure below shows details of an experiment performed by a student and the results taken. (take the density of water as 1.0g/cm3)
i) Calculate the...
(Solved)
The figure below shows details of an experiment performed by a student and the results taken. (take the density of water as 1.0g/cm3)

i) Calculate the volume of the metal block below the water
ii) Calculate the new reading on the compression balance after the block is halfway immersed
iii) Calculate the reading you would expect to obtain on the spring balance
iv) Give a statement of the principle you have used in part (iii) above
Date posted:
May 31, 2019
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Answers (1)
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The figure below shows a stone whirled in a horizontal circle.
Use the information to distinguish between angular velocity and linear speed of the stone.
(Solved)
The figure below shows a stone whirled in a horizontal circle.

Use the information to distinguish between angular velocity and linear speed of the stone.
Date posted:
May 31, 2019
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Answers (1)
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A 50W heating coil is totally immersed in 100g of water contained in an insulated flask of negligible heat capacity. The initial temperature of water...
(Solved)
A 50W heating coil is totally immersed in 100g of water contained in an insulated flask of negligible heat capacity. The initial temperature of water in the flask is 20oc.
i) Determine how long it takes for the water to boil at 100oC when the heater is switched on
ii) After the water has been boiling for 15 minutes, it is found that the mass of water in the flask has decreased to 80g. Assuming no external heat losses, calculate a value for the specific latent heat of vaporization of water
Date posted:
May 31, 2019
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Answers (1)
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The illustration below is used to produce a measured rise in temperature of a liquid using electrical energy.
Explain why;
i) The liquid will tend to be...
(Solved)
The illustration below is used to produce a measured rise in temperature of a liquid using electrical energy.

Explain why;
i) The liquid will tend to be warmer at the top of the container than at the bottom.
ii) The temperature will eventually stop rising even though the current is still passing through the heating coil.
iii) If the apparatus is used to determine the specific heat capacity of the liquid, the accuracy of the experiment will be increased if the liquid is first cooled to about 5oc below room temperature and the current passed until the temperature is about 5oc above room temperature.
Date posted:
May 31, 2019
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Answers (1)
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You are provided with the following
- Test-tube
- Some sand
- Spatula
- Measuring cylinder with water
- Spring balance
Using diagrams describe an experiment to verify law of floatation.
(Solved)
You are provided with the following
- Test-tube
- Some sand
- Spatula
- Measuring cylinder with water
- Spring balance
Using diagrams describe an experiment to verify law of floatation.
Date posted:
May 31, 2019
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Answers (1)