## Electricity Paper 2 Questions and Answers - MECS Cluster Joint Pre Mock Exams 2021/2022

ELECTRICITY
PAPER 2

INSTRUCTIONS TO CANDIDATES

• Candidates should have the following for this examination
• Drawing instruments
• Mathematical tables
• Drawing paper size A3
• All dimensions are in millimeters unless otherwise stated.
• Each question takes 30 mins

Exercise 1

1. using the components, materials and equipment provided, carryout the following tasks
1. Connect the circuit as shown in the figure below. Let the examiner check your work.
2. Vary the base resistance RB to obtain each of the base current IB values shown in table 1. For each value of IB , measure and record in the table the corresponding values of VCE and Ic
 IB (ÂµA) VCE (V) Ic (mA) 200 220 240 260 280 300
3. Using the values in table 1:
1. Determine the current gain Î² when IB =240ÂµA 2mks
2. Plot a graph of Ic against VCE. 5mks

Exercise 2

1. Use tools and materials to fabricate the candle holder shown below.

Exercise 3

1. Use the tools, equipment and materials provided to carry out the following task; a) terminate the three core flexible cable to the top plug and the iron box 15mks.
2. Turn on the thermostat switch to ON position, measure and record the values of resistance between;
1. Live and neutral at plugâ¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦
2. Live and earth at plugâ¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦
3. Earth at plug and iron box bodyâ¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦
4. Neutral at plug and at the iron boxâ¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦5mks.

Exercise 4.

Using components and equipment provided perform the following task. Let the examiner check your work.

1. On the breadboard, connect the circuit components as shown below. 3mks
2. Connect the circuit and measure the voltage and current across and through 470â¦ resistor. Vâ¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦..Iâ¦â¦â¦â¦â¦â¦â¦â¦..2mks
3. Measure and record the values of current and voltage across the 220â¦ resistor.
Vâ¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦.Iâ¦â¦â¦â¦â¦â¦â¦â¦â¦â¦..2mks
4. Measure and record the values of voltage and current
V=â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦..I=â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦2mks
V=â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦..I=,â¦â¦â¦â¦â¦â¦â¦â¦â¦â¦..2mks
5. Calculate the values in ii,iii and iv above and compare them wit the measured value. State the difference obtained. Account for the difference 9mks

Exercise 5

1. Using PVC sheathed wiring, complete the installation shown below. Such that the bell is operated from either A or B. 20mks.

CONFIDENTIAL

EXERCISE 1

1. variable power supply ( 0-30v)
2. Ten 470 ohms carbon resistors
3. Ten 10K carbon resistors
4. Ten 47k variable resistors
5. Ten BC 101 NPN resistors
6. Enough Connecting wires
7. Enough Jumper wires
8. five milli-ammmeters (0-100mA)
9. five micro-ammeters 0-500ÂµA

EXERCISE 2

1. tin snips
2. scriber
3. drilling machine
4. bench vice
5. mallet
6. steel nail
7. soldering gun
8. solder wire

EXERCISE 3

1. iron box (in good condition)
2. multimeters
3. tester
4. screw driver

EXERCISE 4

1. ten 100 ohms resistors
2. ten 470 ohms resistors
3. ten 560 ohms resistors
4. ten 220 ohms resistors
5. power supply
6. enough connecting wires
7. enough jumper wires
9. voltmeters (0-999v)
10. ammeters (0-100mA)

EXERCISE 5

1. consumer control unit
2. ransformer 240v/12v
3. two push buttons
4. 12v bell
5. 1.5mm2 cable twin with earth
6. Electrician tool box
7. Two Shallow patresses

MARKING SCHEME

EXERCISE 1

 Areas to be marked Maximum Score Candidate score Correct connection 3 Sub Total 3

EXERCISE 2

 Areas to be marked Maximum Score Candidates Score Correct dimension 8 Ã Â½ 4 Holes location â correct location 2 Drilling 2 Â½ Cutting 8 Ã Â½ 4 Folding 3 Ã Â½ 1Â½ Flaps formation 2Ã1 2 Soldering 2 Ã 1 2 Finishing 2 Ã 1 2 SUB TOTAL 20

EXERCISE 3

 Areas to be marked Maximum Scoreâ Candidate Score Total marks 20

EXERCISE 4.

 Areas to be marked Maximum Score Candidate Score Correct connection 6Ã 1/2 3 Subtotal 3

EXERCISE 5

 Areas to be marked Maximum score Candidate score Dimension 8 Ã Â½ 4 Fixing components 5 Ã Â½ 3 Vertical cable runs 3 Ã Â½ 2 Horizontal run (flat) 2 Ã Â½ 2 Uniform spacing of clips 2 90o bend 1 Correct circuit connection CCU BELL Bell pushes 3 Correct cable termination (firm and not knicked) CCU 1 Bell 1 Bell pushes 1 SUB TOTAL 20