Notebook

Electrical Engineering MCQ|Objective questions Electrical Engineering|Industries Extension officer|Lecturer in Polytechnics set 4

A short circuit is that which 

Which of the following stays the same in all parts of a series circuit? 

 The resistance of the windings of a generator is known as 

 Ohm‟s law is applicable to 

A wire of length l of a circular cross-section of radius r has a resistance of R ohms. Another wire of same material and a cross-sectional radius 2r will have the same resistance R if the length is 

 With the rise in temperature, the temperature coefficient of resistance 

The values of the temperature coefficient of resistance of a given conductor are‟ 

 Temperature coefficient of resistance is defined as 

 The resistance of a parallel circuit consisting of two resistors is 12Ω. One of the resistance wires breaks and the effective resistance becomes 18Ω. The resistance of the broken wire is 

(a) 48 Ω

When one leg of a parallel circuit gets opened out, the current drawn from the supply will

Electrical Engineering MCQ|Objective questions Electrical Engineering|Industries Extension officer|Lecturer in Polytechnics set 3

Which of the following relation is incorrect 
(a) P = VI
 (b) P=I2R
(c) P= V∕R2
(d) P= V2∕R


 If I, R and t are the current, resistance and time respectively, then according to Joule‟s law heat produced will be proportional to 
(a) I2Rt 
(b) I2Rt2
(c) I2R2t 
(d) I2R2t2



 When a low resistance is connected in parallel with a high resistance, the combined
resistance is ( B )

(a) always more than the high resistance 
(b) always less than the low resistance
(c) always between the value of high and low resistance
(d) either lower or higher than low resistance depending on the value of high resistance

Two 100 W, 200 V lamps are connected in series across a 200 V supply. The total power consumed by each lamp will be watts. ( A )
(a)25 
(b) 50
(c) 100 
(d) 200


The factor which will have least effect on the voltage at the load end of a two-wire supply circuit is ( B )

(a) length of the circuit 
(b) whether supply frequency is 25 Hz or 50 Hz
(c) amount of load on the circuit 
(d) cross section of the current wires


For a given line voltage, four heating coils will produce maximum heat when connected
(a)all in parallel 
(b) all in series 
(c) with two parallel pairs in series 
(d) on pair in parallel with the other two in series


For current to flow, a circuit must be ( C )
(a) Isolated 
(b) insulated
(c) complete 
(d) protected


If a live‟ conductor of a public supply touches earth metal ( D )

(a) supply voltage will increase 
(b) supply voltage will decrease
(c) no current will flow 
(d) current will flow to earth


The material used for fuse must have 
(a) Low melting point and low specific resistance
(b) Low melting point and high specific resistance
(c) High melting point and low specific resistance

 Which of the following statements regarding a capacitor is not true? 
(a) dc cannot flow through it (b) ac can flow through‟ it
(c) current flows when a capacitor is connected for the first time across a battery

(d) slight moisture increases its capacitance

Electrical Engineering MCQ|Objective questions Electrical Engineering|Industries Extension officer|Lecturer in Polytechnics set 2

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 10kΩ, 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 21Ω. If its thickness (diameter) is 0.44 mm, its specific resistance is around 
(a) 1.2 x 10-8Ω-m 
(b) 1.4 x 10-8Ω-m
(c) 1.6 x 10-8Ω-m 
(d) 1.8 x 10-8Ω-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 Ω when connected in series and 6 Ω when joined in parallel. The resistance of each wire is 
(a)10 Ω, 15 Ω 
(b) 20 Ω, 30 Ω
(c) 5 Ω, 10 Ω 
(d) 10 Ω, 20 Ω

10. An instrument which detects electric current is known as 
(a) Voltmeter 
(b) rheostat
(c) wattmeter 
(d) galvanometer