The current of electrons hitting the screen of a cathode ray oscilloscope is 2.0 X 10 “ A .
Determine the number of electrons that strike the screen each second. (take charge qfun electron as 1.6 >< 107” C
The anode of an x-ray tube becomes hot when the tube is in use. State the reason for this.
State two uses of a charged gold leaf electroscope.
Radium undergoes radioactive decay by emitting an alpha particle to form a daughter nuclide Q as in the reaction:
Determine the values of:
(a) x
(b) y
Figure 5 shows a graph of current against voltage for a semiconductor diode.
In the space provided, draw a circuit diagram that may be used to obtain values needed to draw the graph in figure 5
Figure 4 shows the magnetic field pattern around two bar magnets placed side by side.
Indicate on the diagram the poles of each magnet.
It is observed that when the cap of an uncharged electroscope is irradiated with light of high frequency, the leaf of the electroscope rises. Explain this observation.
Figure 3 shows a nail on which a wire is to be wound to make an electromagnet.
By drawing, show how the wire should be wound around the nail so that end A becomes a north pole and end B a south pole.
The frequency of an electromagnetic wave is 4.0 >< l0“ Hz. Determine its wavelength. (take speed oflighz as 3.0 >< I08ms” ).
Figure 2 shows circular waves originating from the principal focus F of a concave mirror and moving towards the mirror.
Complete the diagram to show the reflected waves
