Engineering Answers

A. There are specific tests that must be performed at the end of an installation State the purpose for performing each of the following tests:

 i. Polarity test ii. Earth continuity test iii. Insulation resistance test

With the use of a neat diagram, show the main features of an electrical power system (Grid) typical to that of Jamaica giving appropriate voltages and a brief explanation of what happens at each stage from Power Station to Consumers' residence.

With the use of a suitable diagram explain how a person can get an electrical shock from touching an unearthed isolator, state a precaution that can be taken to prevent a reoccurrence.    

Briefly explain the steps you would take if you witness someone experiencing an electrical Shock at the work place

List the FOUR (4) classes of fire with a brief explanation of each class.

Define fire. With the aid of the fire triangle list the fire possible methods one could employ to extinguish a fire.

Explain the basic operation of a generator using a suitable diagram to support your answer.

The electric bill for a family for a month is $120.

a. Assuming 30 days in the month, what is the cost per day?

b. Based on 15-h days, what is the cost per hour?

c. How many kilowatthours are used per hour if the cost is 12¢/kWh?

d. How many 60 W lightbulbs (approximate number) could you have on to use up that much energy per hour?

e. Do you believe the cost of electricity is excessive?