(i) Ultra Violet (UV) light removes electrons from the zinc plate. The negative charge on the electroscope repels these electrons and as a result the electroscope becomes discharged and therefore the leaf falls.
(ii) The electrons removed by the UV light do not escape due to attraction by positive charge on the electroscope therefore the leaf divergence remain the same.
johnmulu answered the question on June 6, 2017 at 07:03
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In figure 18 ultra-violet (u.v.) light falls on a zinc plate placed on a charged leaf electroscope. It is observed that the leaf collapses.
Explain how this observation may be used to determine the type of charge on the electroscope.
Date posted: June 6, 2017. Answers (1)
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Date posted: June 6, 2017. Answers (1)
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In an experiment on photo-electricity using metal X, the graph shown in Fig.9 was obtained. Use the graph to answer the question.
Determine the minimum frequency,fo, below which no photoelectric emission occurs.
Date posted: June 6, 2017. Answers (1)
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Date posted: June 6, 2017. Answers (1)
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Figure 18 shows the parts of an x-ray tube.
(a) Explain why:
(i) A potential difference is applied to the filament.
(ii) A high potential difference is applied between a cathode and the anode.
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Date posted: June 6, 2017. Answers (1)
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Figure 13 shows the features of an X-ray tube.
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Date posted: June 6, 2017. Answers (1)
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Figure 10 shows the waveform of a signal applied at the y - plates of an oscilloscope whose time-base is switched to the scale of 2 milliseconds per centimeter.
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Date posted: June 6, 2017. Answers (1)
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(i) State how electrons are produced in the tube.
(ii) state how electron beam is detected.
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Date posted: June 6, 2017. Answers (1)
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Date posted: June 6, 2017. Answers (1)
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Figure 14 (a) is a diagram of a cathode ray tube. M and N are parallel vertical plates.
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Date posted: June 6, 2017. Answers (1)
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Figure 14 shows the features of a cathode ray tube.
(i) Name the parts labeled A and B.
(ii) Explain how the electrons are produced in the tube.
(iii) State two functions of the anodes.
(iv) At what part of the cathode ray tube would the time be connected?
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Figure 6 shows a tube for investing the properties of a beam of electrons. Use the information in the figure to answer the question.
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Date posted: June 5, 2017. Answers (1)
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(ii) State and explain the function of the grid.
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the terminals labeled X and Y.
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Date posted: June 5, 2017. Answers (1)
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Date posted: June 5, 2017. Answers (1)
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Date posted: June 5, 2017. Answers (1)
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Date posted: June 5, 2017. Answers (1)