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

.

** .**

**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

632