VpIp = VsIs
12000 x 1 = 1800 x Is
Is = 0.6667A
Power loss = I2R
= 0.66672 x 20 = 8.89w
sharon kalunda answered the question on April 4, 2019 at 10:17
-
State one way through which energy is lost in a transformer and give a remedy for it.
(Solved)
State one way through which energy is lost in a transformer and give a remedy for it.
Date posted:
April 4, 2019
.
Answers (1)
-
A steel bar can be magnetized and not an aluminum bar. Explain
(Solved)
A steel bar can be magnetized and not an aluminum bar. Explain
Date posted:
April 4, 2019
.
Answers (1)
-
The diagram below shows a magnetic field patterns between magnets S and R. use it to answer
questions below:-
(Solved)
The diagram below shows a magnetic field patterns between magnets S and R. use it to answer
questions below:-
(a) Identify the poles A and B
(b) State which of the two magnets R and S is stronger. Explain
Date posted:
April 4, 2019
.
Answers (1)
-
Draw the magnetic field pattern in the figure below and indicate the direction of the force.
(Solved)
Draw the magnetic field pattern in the figure below and indicate the direction of the force.
Date posted:
April 4, 2019
.
Answers (1)
-
Two similar pins were placed one on a wooden block and the other on an iron block. The two
blocks were placed near a magnet. State...
(Solved)
Two similar pins were placed one on a wooden block and the other on an iron block. The two
blocks were placed near a magnet. State and explain the observations noted
Date posted:
April 4, 2019
.
Answers (1)
-
Use the domain theory to differentiate between hard magnetic materials and soft magnetic
materials
(Solved)
Use the domain theory to differentiate between hard magnetic materials and soft magnetic
materials
Date posted:
April 4, 2019
.
Answers (1)
-
The diagram figure below shows one method of making a magnet. Complete the diagram
to make both ends A and B of the cores be North...
(Solved)
The diagram figure below shows one method of making a magnet. Complete the diagram
to make both ends A and B of the cores be North poles
Date posted:
April 4, 2019
.
Answers (1)
-
The diagram figure below shows an electromagnet made by a student of Nyamogo Girls
secondary school, in the laboratory. The magnet was meant to pick up...
(Solved)
The diagram figure below shows an electromagnet made by a student of Nyamogo Girls
secondary school, in the laboratory. The magnet was meant to pick up and release a metal object
(i) Name giving reasons a suitable material for part X
(ii) The electromagnet will just lift a metal of mass 150g. Taking g = 10N/Kg, what will be the
least force exerted by the magnet to do this
(iii) State the changes which the student should make so that a heavier metal object could be
lifted by the magnet
(iv) Explain why the strength of the above magnet cannot be increased indefinitely
Date posted:
April 4, 2019
.
Answers (1)
-
Draw the magnetic field pattern around the magnets below.
(Solved)
Draw the magnetic field pattern around the magnets below.
Date posted:
April 4, 2019
.
Answers (1)
-
Two pins are attached to each of the magnets as shown below.
(Solved)
Two pins are attached to each of the magnets as shown below.
Explain the behaviour of pins in each case.
Date posted:
April 4, 2019
.
Answers (1)
-
The figure below shows a micrometer screw gauge being used to measure the diameter of a rod.
The thimble scale has 50 divisions.
(Solved)
The figure below shows a micrometer screw gauge being used to measure the diameter of a rod.
The thimble scale has 50 divisions.
What is the reading?
Date posted:
April 4, 2019
.
Answers (1)
-
A gold leaf electroscope is positively charged as shown in the diagram in figure where C is the cap and L is the gold leaf....
(Solved)
A gold leaf electroscope is positively charged as shown in the diagram in figure where C is the cap and L is the gold leaf. State and explain what happens to L when a positively charged rod is
brought near C without touching it.
Date posted:
April 4, 2019
.
Answers (1)
-
In the figure below, explain what happens when one of the metal balls comes into contact with
a negatively charged rod.
(Solved)
In the figure below, explain what happens when one of the metal balls comes into contact with
a negatively charged rod.
Date posted:
April 4, 2019
.
Answers (1)
-
Two identical spheres A and B each standing on an insulated base are in contact. A
negatively charged rod is brought near sphere A as shown...
(Solved)
Two identical spheres A and B each standing on an insulated base are in contact. A
negatively charged rod is brought near sphere A as shown below
In what way will A differ from B if separated while the rod is near?
Date posted:
April 4, 2019
.
Answers (1)
-
Two metal cons A and B of different sizes rest on two identical gold leaf electroscope as shown.
(Solved)
Two metal cons A and B of different sizes rest on two identical gold leaf electroscope as shown.
Compare the divergence of the gold leaves of the two electroscopes. Explain your answer
Date posted:
April 4, 2019
.
Answers (1)
-
The figure below shows an uncharged pith ball under the attraction of a charged ball.
(Solved)
The figure below shows an uncharged pith ball under the attraction of a charged ball.
State and explain what would be observed after the two pith balls touch
Date posted:
April 4, 2019
.
Answers (1)
-
The length of a pinhole camera is 20cm. Determine the height of a storey building 300m away
from the pin hole if the image formed on...
(Solved)
The length of a pinhole camera is 20cm. Determine the height of a storey building 300m away
from the pin hole if the image formed on the screen of the pin hole camera is 2.5cm high
Date posted:
April 4, 2019
.
Answers (1)
-
Explain why transformers are widely used throughout the national grid system
(Solved)
Explain why transformers are widely used throughout the national grid system
Date posted:
April 4, 2019
.
Answers (1)
-
A coil of wire is connected in series with a battery, a rheostat and a switch as shown in figure
(Solved)
A coil of wire is connected in series with a battery, a rheostat and a switch as shown in figure
(i) Draw on the diagram, the shape of the magnetic field inside and outside the coil when the
switch is closed.
If the jockey J on the rheostat is moved towards Q what’s the effect on:-
(ii)The resistance of the circuit
(iii) The current through the coil
(iv) The magnetic field in the coil
Date posted:
April 4, 2019
.
Answers (1)
-
A student hung a magnet next to a coil of wire to make a door chime as shown in figure :-
(Solved)
A student hung a magnet next to a coil of wire to make a door chime as shown in figure :-
i) Explain how the current made the magnet move towards the chime bar
(ii) What should the student do to make the magnet hit the chime bar harder?
Date posted:
April 4, 2019
.
Answers (1)