K.C.S.E Physics Q & A - MODEL 2016PP2QN12
.When germanium crystal is doped with arsenic, it becomes an N-type semiconductor. Explain how this change occurs.
(Number of electrons in the outermost shell for germanium =4, arsenic =5)
K.C.S.E Physics Q & A - MODEL 2015PP2QN13
When a transformer is connected to an ac source, the output voltage is found to be 24 V. If the power input is 200 W, determine the output current. (Assume the transformer is 100% efficient)
K.C.S.E Physics Q & A - MODEL 2014PP2QN08
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.
K.C.S.E Physics Q & A - MODEL 2013PP2QN13
When a germanium crystal is doped with arsenic, it becomes an N-type semiconductor. Explain how this change occurs.
(Number of electrons in the outermost shell for germanium = 4. Arsenic = 5)
K.C.S.E Physics Q & A - MODEL 2011PP2QN19
(a) When a radiation was released into a diffusion cloud chamber, short thick tracks were observed. State with a reason, the type of radiation that was detected.
(b) The half-life of an element X is 3.83 days. A sample of this element is found to have an activity rate of 1.6 x 103 disintegrations per second at a particular time.
Determine its activity rate after 19.15 days.
(c) State what is meant by an extrinsic semiconductor.
(d) Figure 12, shows a depletion layer in an unbiased p-n junction.
State how a battery can be used to make the depletion layer narrower.
(e) Figure 13, shows an incomplete circuit of a full wave rectifier
(I) Draw in the figure two more diodes to complete the circuit.
(ii) Show on the figure the points across which the output of the rectifier should obtained.
FORM I - PHYSICS SYLLABUS
FORM II - PHYSICS SYLLABUS
FORM III - PHYSICS SYLLABUS
FORM IV - PHYSICS SYLLABUS
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