Electromagnet can easily be magnetized and de-magnetized unlike the permanent magnet.
Kavungya answered the question on May 27, 2019 at 06:22
- 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. Answers (1)
- 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. Answers (1)
- A body starts from rest and accelerated uniformly at 8 m/s2. Calculate the distance traveled
by the body in 10 seconds.(Solved)
A body starts from rest and accelerated uniformly at 8 m/s2. Calculate the distance traveled
by the body in 10 seconds.
Date posted: May 27, 2019. Answers (1)
- The figure below shows a pulley system for lifting heavy object.
(i) State the velocity ratio of the pulley system.
(ii) If the efficiency of the...(Solved)
The figure below shows a pulley system for lifting heavy object.
(i) State the velocity ratio of the pulley system.
(ii) If the efficiency of the machine is 80%. Calculate the mechanical advantage of the system.
(iii) Determine the effort applied.
Date posted: May 27, 2019. Answers (1)
- A car of mass 900 kg collided heads on with a truck of mass 4000 kg travelling at 40 m/s.
The car is thrown on the...(Solved)
A car of mass 900 kg collided heads on with a truck of mass 4000 kg travelling at 40 m/s.
The car is thrown on the bonnet of the truck, which continues to move after impact at
10 m/s in its original direction. What was the speed of the car?
Date posted: May 27, 2019. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- A body of a mass 0.6 is attached to the end of a string of length 50 cm and whirled in a
horizontal circle. If the...(Solved)
A body of a mass 0.6 is attached to the end of a string of length 50 cm and whirled in a
horizontal circle. If the tension of the string is 96 N. Determine the velocity of the body.
Date posted: May 27, 2019. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- 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. Answers (1)
- The table below shows part of the electromagnetic spectrum in order of decreasing wavelength.
a) How are waves C produced?
b) State one use of the...(Solved)
The table below shows part of the electromagnetic spectrum in order of decreasing wavelength.
a) How are waves C produced?
b) State one use of the wave D.
Date posted: May 25, 2019. Answers (1)