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Form 4 physics cathode rays and cathode ray tube question and answers

Form 4 physics cathode rays and cathode ray tube topical question and answers. The questions are suitable for those preparing for both class exams as well as KCSE exams.

Lessons (11)

• 1.    The control grids in a Cathode Ray Oscilloscope (CRO) is used to control the brightness of the beam on the screen. How is this achieved?
  0m 55s

• 2.    State two differences between the cathode ray tube (CRT) of a T.V and the cathode ray oscilloscope (CRO).
  1m 17s

• 3.    Figure 22 shows an electric generator. The points P and Q are connected to a cathode ray oscilloscope (CRO). Sketch on the axis provided, the graph of the voltage output as seen on the CRO, given that when t=0, the coil is at the position shown in the figure.
  1m 59s

• 4.    Figure 3 shows the main features of a cathode ray tube (CRT) of a cathode ray oscilloscope (CRO). (i) Describe how the electrons are produced in the tube. (ii) State and explain the function of the grid. (iii) State what would be observed on the screen if an a.c voltage is connected across the y-plates. (iv) State how the deflection system of a television differs from that of a CRO.
  4m 39s

• 5.    The circuit figure 14 represents a simple radio receiver. On the axes provided, sketch the waveform observed on the CRO for the signal shown.
  0m 53s

• 6.    Figure 18 shows the pattern produced by an A.C voltage on a CRO screen. On the same figure, sketch the pattern produced by the same voltage when the time base is switched off.
  1m 8s

• 7.    Figure 17 shows the appearance of an alternating signal on a screen of a cathode ray oscilloscope. On the same diagram, sketch the appearance of the signal when the frequency is doubled and the voltage halved.
  1m 47s

• 8.    Figure 6 shows a tube for investigating the properties of a beam of electrons. Use the information in the figure to answer question 8. What property of the beam of electrons shows that the electrons are travelling at a very high speed?
  1m 20s

• 9.    Figure 6 shows a tube for investing the properties of a beam of electrons. Use the information in the figure to answer question 9. The beam of electrons is subjected to a strong magnetic field which is perpendicular to the path and into the paper. Sketch on the same figure, the new path of electrons.
  1m 15s

• 10.    (a) Figure 9 shows a cathode ray tube in which a beam of electrons is cast on the screen. (i) State how electrons are produced in the tube. (ii) State how the electron beam is detected. (iii) State the reason for having a variable potential difference (p.d) at the: (I) Grid (II) Anodes (b) Figure 10 shows the waveform of a signal applied at the y-plates of an oscilloscope whose time-base is switch
  4m 0s

• 11.    Figure 4 shows a cathode ray entering into a region between two charged plates. Complete the diagram to show the path of the ray in the field.
  0m 55s