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A temperature increase causes the brass tube to expand and move to the left. The invar rod also moves with it and causes the valve to partially close. This reduces the gas inflow. A decrease in temperature causes the brass tube to contract and move the valve forward. The movement opens the entrance and increases the flow of gas to the burners
Kavungya answered the question on May 31, 2019 at 09:17
- The distance between the ice point and steam point on a liquid in glass thermometer is 30cm. what temperature is recorded when the mercury thread...(Solved)
The distance between the ice point and steam point on a liquid in glass thermometer is 30cm. what temperature is recorded when the mercury thread is 12cm above the ice point?
Date posted: May 31, 2019. Answers (1)
- A single spring stretches by 2.0 cm when supporting a load of 50N. If in the system below the springs are identical and have negligible...(Solved)
A single spring stretches by 2.0 cm when supporting a load of 50N. If in the system below the springs are identical and have negligible weight
Find:
a) The total extension of the system.
b) The total spring constant.
Date posted: May 31, 2019. Answers (1)
- Give one feature that makes parabolic mirrors suitable for use as car head light.(Solved)
Give one feature that makes parabolic mirrors suitable for use as car head light.
Date posted: May 31, 2019. Answers (1)
- The figure below shows a defective eye.
i) State the cause of the defect.
ii) What type of lens is used to correct the defect?(Solved)
The figure below shows a defective eye.
i) State the cause of the defect.
ii) What type of lens is used to correct the defect?
Date posted: May 31, 2019. Answers (1)
- The figure below shows an object placed infront of a thin lens. The focal length of the lens is 10cm. The screen is adjusted
until an...(Solved)
The figure below shows an object placed infront of a thin lens. The focal length of the lens is 10cm. The screen is adjusted
until an image which is magnified 5 times is obtained.
From the information:
a) i) Which type of lens was used in the experiment.
ii) State any other characteristics of the image formed.
iii) Find the value of u.
Date posted: May 31, 2019. Answers (1)
- The figure below shows ultraviolet radiation striking polished zinc plates placed on negatively and positively charged gold
leaf electroscopes respectively.
Explain why the leaf collapses in figure...(Solved)
The figure below shows ultraviolet radiation striking polished zinc plates placed on negatively and positively charged gold
leaf electroscopes respectively.
Explain why the leaf collapses in figure (a) but does not collapse in figure (b).
Date posted: May 31, 2019. Answers (1)
- The diagram below shows a micrometer screw gauge used by a student to measure the thickness of a wire. If it has a zero error...(Solved)
The diagram below shows a micrometer screw gauge used by a student to measure the thickness of a wire. If it has a zero error of 0.06mm, what is the actual thickness of the wire?
Date posted: May 31, 2019. Answers (1)
- State two advantages of the use of alternating voltage for the transmission of electrical energy.(Solved)
State two advantages of the use of alternating voltage for the transmission of electrical energy.
Date posted: May 31, 2019. Answers (1)
- A transformer is used to provide a potential difference of 100KV to an X-ray tube from 250V a.c mains supply. A current of 100mA flows...(Solved)
A transformer is used to provide a potential difference of 100KV to an X-ray tube from 250V a.c mains supply. A current of 100mA flows in ht X-ray tube and the transformer is 100% efficient. Calculate:-
(i) The ratio of the number of turns of the secondary coil to the number of turns in the primary coil.
(ii) The current in the primary coil.
(iii) State giving reasons which of the coils of the transformer is thinner.
Date posted: May 31, 2019. Answers (1)
- State one difference and one similarity between a step up transformer and an induction coil.(Solved)
State one difference and one similarity between a step up transformer and an induction coil.
Date posted: May 31, 2019. Answers (1)
- The figure below shows a simple transformer. Study it and answer the questions that follow.
i) Explain why the core is a continuous loop.
ii) Give...(Solved)
The figure below shows a simple transformer. Study it and answer the questions that follow.
i) Explain why the core is a continuous loop.
ii) Give a reason as to why the core is laminated.
iii) State and explain which coils are thicker.
Date posted: May 31, 2019. Answers (1)
- The figure below shows a ray of light incidents on glass-air interface.
Given that the refractive index of glass is 1.48, determine the value of theta.(Solved)
The figure below shows a ray of light incidents on glass-air interface.
Given that the refractive index of glass is 1.48, determine the value of theta.
Date posted: May 31, 2019. Answers (1)
- In the figure below the bar magnet is moved into the coil.
(i) State and explain what is observed in the galvanometer.
(ii) Explain briefly the...(Solved)
In the figure below the bar magnet is moved into the coil.
(i) State and explain what is observed in the galvanometer.
(ii) Explain briefly the source of an electrical energy in the circuit.
Date posted: May 31, 2019. Answers (1)
- In an experiment to determine the refractive index of a liquid, the liquid was poured into a measuring cylinder, a pin was
placed at the bottom...(Solved)
In an experiment to determine the refractive index of a liquid, the liquid was poured into a measuring cylinder, a pin was
placed at the bottom of the cylinder and another pin was used to locate the apparent position of the first pin. The values
of real and apparent depth were used to plot a graph in the figure below.
i) From the graph determine the refractive index of the liquid.
ii) Given that the velocity of light in vacuum is 3.0 x 108 m/s what would be the velocity of light in the liquid
above.
Date posted: May 31, 2019. Answers (1)
- The figure below shows an object O placed in front of an objective lens Lo whose focal length fo is less than fe, the focal...(Solved)
The figure below shows an object O placed in front of an objective lens Lo whose focal length fo is less than fe, the focal length of the eyepiece Le. Complete using ray construction how the arrangement would produce a compound microscope.
Date posted: May 31, 2019. Answers (1)
- The initial mass of a radioactive substance is 20g. The substance has a half -life of 5 years. Determine the mass remaining after 20 years.(Solved)
The initial mass of a radioactive substance is 20g. The substance has a half -life of 5 years. Determine the mass remaining after 20 years.
Date posted: May 31, 2019. Answers (1)
- The diagram below shows an arrangement of capacitors in a circuit.
Determine:-
(i) The total capacitance
(ii) The total charge
(iii) The energy stored by the 2µF...(Solved)
The diagram below shows an arrangement of capacitors in a circuit.
Determine:-
(i) The total capacitance
(ii) The total charge
(iii) The energy stored by the 2μF capacitor.
Date posted: May 31, 2019. Answers (1)
- Explain why carbon -14 is radioactive while Carbon -12 is not.(Solved)
Explain why carbon -14 is radioactive while Carbon -12 is not.
Date posted: May 31, 2019. Answers (1)
- The cell in the figure below has an e.m.f. of 1.8V and negligible internal resistance.
Determine:-
(i) Total resistance in the circuit.
(ii) The current in the...(Solved)
The cell in the figure below has an e.m.f. of 1.8V and negligible internal resistance.
Determine:-
(i) Total resistance in the circuit.
(ii) The current in the circuit.
(iii) Reading of the voltmeter.
Date posted: May 31, 2019. Answers (1)
- The figure below shows an object O infront of a concave mirror and its image, I, formed after reflection.
On the same diagram draw appropriate ray(s)...(Solved)
The figure below shows an object O infront of a concave mirror and its image, I, formed after reflection.
On the same diagram draw appropriate ray(s) to locate the principal focus F, of the mirror.
Date posted: May 31, 2019. Answers (1)