Electrical Questions
Underlined is correct Answer


1. Which one of the following fireextinguisher is suitable for a live electrical fire?

A. halon

B. water

C. foam

D. liquefied chemical

2. A heater draws a current of 8A whenconnected to a 240V source. What is the resistance value of the heater elementin ohms?

A. 40

B. 20

C. 30

D. 60

3. An electric soldering iron with an 80ohms heating element is plugged into a 240V outlet. How much current will bedrawn by the iron?

A. 2A

B. 3A

C. 4A

D. 5A

4. The alternator in a car delivers 4Aand has a load of 3 ohms connected across its terminals. Find the voltage ofthe circuit

A. 18V

B. 24V

C. 12V

D. 16V

.

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5. Three resistors of 1K ohms, 2K ohmsand 7K ohms are connected in series with a 30 V supply. If 2 K ohms and 7 Kohms resistors are open circuited, a voltmeter connected across the 7K ohmsresistor will indicate…

A. 10 k ohms, 3A

B. 10 k ohms, 300mA

C. 10 k ohms, 3 mA

D. 5 k ohms, 6 mA

6. A voltage source produces an IR dropof 40V across a 20 ohms resistance, 60V across a 30 ohms resistance and 180Vacross a 90 ohms resistance all in series. How much is the applied voltage?

A. 180 V

B. 240 V

C. 100 V

D . 280 V

7. Three resistors 27 ohms, 47 ohms and68 ohms are connected in parallel. What is the otal resistance?

A. less than 27 ohms  

B. greater than 68 ohms  

C. between 27 and 47 ohms  

D. sum of all the three resistances

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