Electromagnet can easily be magnetized and de-magnetized unlike the permanent magnet.
Kavungya answered the question on May 27, 2019 at 06:22
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An immersion water heater rated 1800 w is used to heat water from 100C to 900C. Calculate the time taken, if the mass of water...
(Solved)
An immersion water heater rated 1800 w is used to heat water from 100C to 900C. Calculate the time taken, if the mass of water is 6 kg. (Take specific heat capacity of water as 4200J kg -1K-1)
Date posted:
May 27, 2019
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Answers (1)
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A student heated some pure water and noticed it boiled at 960C instead of 1000C. If the thermometer was not faulty, what is the possible...
(Solved)
A student heated some pure water and noticed it boiled at 960C instead of 1000C. If the thermometer was not faulty, what is the possible cause for this?
Date posted:
May 27, 2019
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Answers (1)
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A cork of volume 200 cm3 is floating on water. If the density of the cork is 0.25 g/cm3.
Calculate;
(i) the mass of the cork.
(ii)...
(Solved)
A cork of volume 200 cm3 is floating on water. If the density of the cork is 0.25 g/cm3.
Calculate;
(i) the mass of the cork.
(ii) the upthrust force on the cork.
(iii) the minimum force required to immerse the cork completely.
Date posted:
May 27, 2019
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Answers (1)
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In the diagram below determine the weight of the metre rule shown below.
(Solved)
In the diagram below determine the weight of the metre rule shown below.
Date posted:
May 27, 2019
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Answers (1)
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An object of mass, m1 has weight, w1 in air and w2 in water. Explain which of two weights is greater than the other.
(Solved)
An object of mass, m1 has weight, w1 in air and w2 in water. Explain which of two weights is greater than the other.
Date posted:
May 27, 2019
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Answers (1)
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An object of density 9 x 102 and mass 1.8 kg is completely immersed in water. Calculate the mass of water displaced in kg. (Take...
(Solved)
An object of density 9 x 102 and mass 1.8 kg is completely immersed in water. Calculate the mass of water displaced in kg. (Take density of water as 1000 kg / m3)
Date posted:
May 27, 2019
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Answers (1)
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An object of weight 18 N attached at the end of a spring causes an extension of 0.3 cm on the spring. Determine the spring...
(Solved)
An object of weight 18 N attached at the end of a spring causes an extension of 0.3 cm on the spring. Determine the spring constant.
Date posted:
May 27, 2019
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Answers (1)
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2000 cm2 of air at 270C is heated to 970C. Determine the new volume if the pressure remains constant.
(Solved)
2000 cm2 of air at 270C is heated to 970C. Determine the new volume if the pressure remains constant.
Date posted:
May 27, 2019
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Answers (1)
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A water pipe of diameter 4.4 cm is connected to another pipe of diameter 1.1 cm. The speedof the water in the smaller pipe is...
(Solved)
A water pipe of diameter 4.4 cm is connected to another pipe of diameter 1.1 cm. The speedof the water in the smaller pipe is 4 m/s. What is the speed, V1 of water in the larger pipe?
Date posted:
May 27, 2019
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Answers (1)
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A ball is thrown horizontally at 8m/s from the tower. It reaches the ground after 4 seconds.Calculate the height of the tower.
(Solved)
A ball is thrown horizontally at 8m/s from the tower. It reaches the ground after 4 seconds.Calculate the height of the tower.
Date posted:
May 27, 2019
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Answers (1)
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The weight of an object on earth is 40 N. If the object weighs 35 N in another planet, determine the gravitational field strength at...
(Solved)
The weight of an object on earth is 40 N. If the object weighs 35 N in another planet, determine the gravitational field strength at that planet. (Take g = 10 N/kg)
Date posted:
May 27, 2019
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Answers (1)
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The figure below shows a micrometer screw gauge used to measure the diameter of a metal rod. When the rod is removed and the jaws...
(Solved)
The figure below shows a micrometer screw gauge used to measure the diameter of a metal rod. When the rod is removed and the jaws of the gauge are closed the reading is 0.14 mm. Determine the diameter of the rod.
Date posted:
May 27, 2019
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Answers (1)
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Figure below shows circular waves approaching a concave reflector.
Show the reflected waves.
(Solved)
Figure below shows circular waves approaching a concave reflector.
Show the reflected waves.
Date posted:
May 25, 2019
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Answers (1)
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Calculate the cost of using the following appliances in one month (30 days ) if the company rate is ksh. 9.50 per unit.
i) A 2000W...
(Solved)
Calculate the cost of using the following appliances in one month (30 days ) if the company rate is ksh. 9.50 per unit.
i) A 2000W water heater for 2 hours per day.
ii) A 75W bulb for 10 hour per day.
iii) A 1500W electric iron for 1 hour per day.
Date posted:
May 25, 2019
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Answers (1)
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A transformer with 2000 turns in the primary circuit and 150 turns in the secondary circuit has its primary circuit connected to a 800V a.c...
(Solved)
A transformer with 2000 turns in the primary circuit and 150 turns in the secondary circuit has its primary circuit connected to a 800V a.c source. It is found that when a heater is connected to the secondary circuit, it produced heat at the rate of 1000W. Assuming 100% efficiency, determine the;
i) Voltage in the secondary circuit.
ii) Current in the primary circuit.
iii) Current in the secondary circuit.
iv) State the type of transformer represented above.
Date posted:
May 25, 2019
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Answers (1)
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A boy watching fireworks display sees the light from an explosion and hears the sound 2.5 seconds later. Determine how far is the explosion. (Speed...
(Solved)
A boy watching fireworks display sees the light from an explosion and hears the sound 2.5 seconds later. Determine how far is the explosion. (Speed of sound in air 330m/s).
Date posted:
May 25, 2019
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Answers (1)
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Figure below shows a path of a ray of light through a rectangular block of Perspex placed in air.
Calculate the refractive index of Perpex.
(Solved)
Figure below shows a path of a ray of light through a rectangular block of Perspex placed in air.
Calculate the refractive index of Perpex.
Date posted:
May 25, 2019
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Answers (1)
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An electric heater is found to have a resistance of 950 ohms when operating normally on a 240V mains. Find the power rating of the...
(Solved)
An electric heater is found to have a resistance of 950Ω when operating normally on a 240V mains. Find the power rating of the heater.
Date posted:
May 25, 2019
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Answers (1)
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Figure below shows a ray of light incident along the normal. The mirror is rotated at an angle of 15o in a clockwise direction without...
(Solved)
Figure below shows a ray of light incident along the normal. The mirror is rotated at an angle of 15o in a clockwise direction without changing the position of the incident ray,
Determine the angle between the reflected ray and the incident ray.
Date posted:
May 25, 2019
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Answers (1)
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The figure below shows water waves of different wave length incident on aperture which is greater than the wavelength of the wave.Complete the diagram...
(Solved)
The figure below shows water waves of different wavelength incident on aperture which is greater than the wave length of the wave.
Complete the diagram to show the pattern of the wave beyond the aperture.
Date posted:
May 25, 2019
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Answers (1)