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- A transformer is designated to work from a 240V a.c. mains and to give a supply of 8V
to ring house bells. The primary has 4800...(Solved)
A transformer is designated to work from a 240V a.c. mains and to give a supply of 8V
to ring house bells. The primary has 4800 turns.
(i) What type of transformer is this? Give a reason.
(ii) Why is the iron core laminated?
(iii) Calculate the secondary turns if the efficiency is 100%.
Date posted: April 4, 2019. Answers (1)
- Study the circuit diagram shown below.(Solved)
Study the circuit diagram shown below.
(i) Determine the reading of the voltmeter V.
(ii) Determine the reading of the ammeter A.
(iii) Explain the effect on the reading of the voltmeter if the 3ohms resistor is altered to be 6ohms
Date posted: April 4, 2019. Answers (1)
- In the configuration of resistors given below, determine the current through the 5ohms resistor.(Solved)
In the configuration of resistors given below, determine the current through the 5ohms resistor.
Date posted: April 4, 2019. Answers (1)
- The ammeter in the circuit below has negligible internal resistance. The cell has internal
resistance of 0.5? and an electromotive force of 3.0V(Solved)
The ammeter in the circuit below has negligible internal resistance. The cell has internal
resistance of 0.5ohms and an electromotive force of 3.0V
Determine the value of current the ammeter registers when switch S is closed
Date posted: April 4, 2019. Answers (1)
- In figure the voltmeter reads 2.1V when the switch is closed, the voltmeter reads 1.8v and
the ammeter 0.1 A(Solved)
In figure the voltmeter reads 2.1V when the switch is closed, the voltmeter reads 1.8v and
the ammeter 0.1 A
Determine:
i) The e.m.f of the cell
ii) The internal resistance of the cell
iii) The resistance of the of the lamp
Date posted: April 4, 2019. Answers (1)
- Three resistors of resistance 2.0ohms and 6.0ohms are connected together in a circuit. Draw
a circuit diagram to show the arrangement of the resistors which gives(Solved)
Three resistors of resistance 2.0ohms and 6.0ohms are connected together in a circuit. Draw
a circuit diagram to show the arrangement of the resistors which gives
i) Effective resistance of 3.0ohms
ii) Minimum resistance
Date posted: April 4, 2019. Answers (1)
- The ammeter in the figure below shows a reading of 2A. What is the reading of the
voltmeter v.?(Solved)
The ammeter in the figure below shows a reading of 2A. What is the reading of the
voltmeter v.?
Date posted: April 4, 2019. Answers (1)
- A lady uses a ramp to lift 1500N load though a vertical distance of 10m. The ramp makes an
angle 30o to the horizontal. If the...(Solved)
A lady uses a ramp to lift 1500N load though a vertical distance of 10m. The ramp makes an
angle 30o to the horizontal. If the efficiency of the ramp is 75%:
(i) Calculate the V.R of the machine
(ii) Find the mechanical advantage
iii) Find the effort needed to move the load up the ramp at constant velocity
Date posted: April 4, 2019. Answers (1)
- A car starting from rest accelerated uniformly for 5minutes to reach 30m/s. it continues at this speed for the next 20minutes and then decelerates uniformly...(Solved)
A car starting from rest accelerated uniformly for 5minutes to reach 30m/s. it continues at this speed for the next 20minutes and then decelerates uniformly to come to a stop in 10minutes. On the axes provided, sketch the graph of the velocity against time for the motion of the car.
Date posted: April 4, 2019. Answers (1)
- A footballer kicks a ball of mass 0.6kg initially at rest using a force of 720N. If the foot was in
contact with the ball 0.1seconds,...(Solved)
A footballer kicks a ball of mass 0.6kg initially at rest using a force of 720N. If the foot was in
contact with the ball 0.1seconds, what was the take off speed of the ball?
Date posted: April 4, 2019. Answers (1)
- A boy is standing between two cliffs A and B but nearer to cliff A than B. He stands 160m
from wall BA and shouts once....(Solved)
A boy is standing between two cliffs A and B but nearer to cliff A than B. He stands 160m
from wall BA and shouts once. He hears two echoes and discovers that the time between the
two echoes is 0.8 seconds. Determine how far the boy is standing from cliff B given that the
speed of sound in air is 340m/s
Date posted: April 4, 2019. Answers (1)
- A lady holds a large concave mirror of focal length 1.8m from her face. State two
characteristics of her image in the mirror(Solved)
A lady holds a large concave mirror of focal length 1.8m from her face. State two
characteristics of her image in the mirror
Date posted: April 4, 2019. Answers (1)
- An object is placed 12cm from a convex mirror of radius of curvature 20cm. Calculate
the position of the image(Solved)
An object is placed 12cm from a convex mirror of radius of curvature 20cm. Calculate
the position of the image
Date posted: April 4, 2019. Answers (1)
- By use of a ray; diagram, show how a concave mirror may be a dentist mirror(Solved)
By use of a ray; diagram, show how a concave mirror may be a dentist mirror
Date posted: April 4, 2019. Answers (1)
- The figure below shows an object placed in front of a plane mirror. Draw appropriate rays to
locate the image as seen by the observer.(Solved)
The figure below shows an object placed in front of a plane mirror. Draw appropriate rays to
locate the image as seen by the observer.
Date posted: April 4, 2019. Answers (1)
- Figure shows an object O being viewed using two inclined mirrors M1 and M2. Complete
the diagram by sketching rays to show the position of the...(Solved)
Figure shows an object O being viewed using two inclined mirrors M1 and M2. Complete the diagram by sketching rays to show the position of the image as seen by the eye -E.
Date posted: April 4, 2019. Answers (1)
- What is meant by the term spherical aberration?(Solved)
What is meant by the term spherical aberration?
Date posted: April 4, 2019. Answers (1)
- The figure below shows two mirrors inclined at an angle of 30o to each other. A ray of light is
incident on one mirror as shown(Solved)
The figure below shows two mirrors inclined at an angle of 30o to each other. A ray of light is
incident on one mirror as shown
Sketch the path of the ray to show its reflection on the two mirrors
Date posted: April 4, 2019. Answers (1)
- Complete the ray diagram to show the position of the image(Solved)
Complete the ray diagram to show the position of the image
Date posted: April 4, 2019. Answers (1)
- Complete the diagram below to show the shape of the wave fronts after passing the gap(Solved)
Complete the diagram below to show the shape of the wave fronts after passing the gap
Date posted: April 4, 2019. Answers (1)