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**Electrical Engineering MCQ|Objective questions Electrical Engineering|Industries Extension officer|Lecturer in Polytechnics**

One commercial unit of energy equals

(a) 500 watt-seconds

(b) one watt-hour

**(c)One kilowatt-hour**

(d) ten kilowatt-hour

The electrical energy required to heat a bucket of water to a certain temperature is 4 kWh. If the heat losses are 20 percent, the energy input is

(a) 2 kWh

(b) 3.2 kWh

**(c) 5 k Wh**

(d) 6 k Wh

3. The maximum current rating for a 10kÎ©, 0.5 W resistor is

(a) 0.707 mA

**(b) 7.07 mA**

(c) 14.14 mA

(d) 28.28 mA

The substances which have a large number of free electrons and offer a low resistance

are called

(a) Insulators (b) inductors

(c)Semi-conductors (

**d) conductors**

The resistance of a conductor varies inversely as

(a) length

**(b) area of cross-section**

(c) temperature

(d) resistivity

With rise in temperature the resistance of pure metals

**(a) Increases**

(b) decreases

(c) first increases and then decreases

(d) remains constant

The resistance of a copper wire 200 m long is 21Î©. If its thickness (diameter) is 0.44 mm, its specific resistance is around

(a) 1.2 x 10-8Î©-m

(b) 1.4 x 10-8Î©-m

**(c) 1.6 x 10-8Î©-m**

(d) 1.8 x 10-8Î©-m

Three resistances of 10 ohms, 15 ohms and 30 ohms are connected in parallel. The total resistance of the combination is

**(a)5 ohms**

(b) 10 ohms

(c)15 ohms

(d) 55 ohms

9. The resistance of two wires is 25 Î© when connected in series and 6 Î© when joined in parallel. The resistance of each wire is

**(a)10 Î©, 15 Î©**

(b) 20 Î©, 30 Î©

(c) 5 Î©, 10 Î©

(d) 10 Î©, 20 Î©

10. An instrument which detects electric current is known as

(a) Voltmeter

(b) rheostat

(c) wattmeter

**(d) galvanometer**

Mam,could u input the solutions of the above problems??

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