Electricity Paper 2 Questions - Mincks Group of Schools Mock Examinations 2022

1. Write your name and index no on the spaces provided
2. Sign and write the date of examination on the spaces provided
3. There are five exercises in this paper
4. Candidates are allowed 30 min for each exercise
5. Attempt all the five exercises as directed by the examiner
6. All dimensions are in mm unless otherwise

QUESTIONS

1. Connect the circuit as shown in figure 1.
   
2. With the switch S open, adjust the power supply to 12v. Let the examiner check your work.
3. Adjust the variable resistor to obtain the current values shown in tables 1. For each of the current values, measure and record the corresponding voltages.
   Table 1
   

   I(mA)	10	20	30	40	50	60
   VR(V)

   (6 Marks)
4. Adjust the potentiometer to 1KΩ. Measure and record the current through.
   1. R1
   2. R2

Use the tools, equipment and materials provided to fabricate the object shown in FIGURE 2 below. (20mks) 

FIGURE 2

1. Connect the circuit as shown in figure 3.
   
   Let the examiner check your work.
2. Adjust Vcc to the values shown in table 2 and for each voltage value measure and record the corresponding value of the collector current, Ic.
   Table 2
   

   Vcc (V)	9	7	5	3	1	0.5
   Ic (mA)

   (6 marks)
3. Repeat step in (b) above for the Vcc values shown in table 3 and complete the table
   Table 3
   

   Vcc (v)	10	8	6	4	2	0.5
   Ic (mA)

   (3 marks)
4. From the results obtained in (b) and (c) above, make two comments about the collector current Ic. (4 marks)
5. State two factors that determine the value of collector current (2 marks)

Figure 5 below shows a layout of a lighting circuit. Using PVC conduit wiring system, install the circuit such that the lamp is independently controlled by S1 and S2.