## Multiple Choice Questions(MCQ) on Current Electricity

1. The Resistance of Human body is around
(a) 5 ohms
(b) 25 ohms
(c) 250 ohms
(d) 1000 ohms

Ans: d

2. The draft velocity of electrons is
(a) very small as compared to the speed of light
(b) equal to the speed of light
(c) almost equal to the speed of light
(d) greater than the speed of light

Ans: a

3. In gases, the flow of current is due to
(a) electron only
(b) positive ions only
(c) electrons and positive ions
(d) electrons, positive ions and negative ions

Ans: d

4. Which of the following material has nearly zero temperature co-efficient of resistance?
(a) Manganin
(b) Porcelain
(c) Carbon
(d) Copper

Ans: a

5. A resistance having rating 10 ohms, 10 W is likely to be a
(a) metallic resistor
(b) carbon resistor
(c) wire wound resistor
(d) variable resistor

Ans: c

6. Varistors are
(a) insulators
(b) non-linear resistors
(c) carbon resistors
(d) resistors with zero temperature coefficient

Ans: b

7. The rating of a fuse wire is always expressed in
(a) ampere-hours
(b) ampere-volts
(c) kWh
(d) amperes

Ans: d

8. The resistance of a few meters of wire conductor in closed electrical circuit is
(a) practically zero
(b) low
(c) high
(d) very high

Ans: a

9. If a parallel circuit is opened in the main line, the current
(a) increases in the branch of the lowest resistance
(b) increases in each branch
(c) is zero in all branches
(d) is zero in the highest resistive branch

Ans: c

10. A closed switch has a resistance of
(a) zero
(d) infinity

Ans: a

11. The insulation on a current carrying conductor is provided
(a) to prevent leakage of current
(b) to prevent shock
(c) both of above factors
(d) none of above factors

Ans: c

12. The thickness of insulation provided on the conductor depends on
(a) the magnitude of voltage on the conductor
(b) the magnitude of current flowing through it
(c) both (a) and (b)
(d) none of the above

Ans: a

13. A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will
(a) decrease
(b) increase
(c) remain same
(d) heater will burn out

Ans: b

14. When electric current passes through a metallic conductor, its temperature rises. This is due to
(a) collisions between conduction electrons and atoms
(b) the release of conduction electrons from parent atoms
(c) mutual collisions between metal atoms
(d) mutual collisions between conducting electrons

Ans: a

15. A glass rod when rubbed with silk cloth is charged because
(a) it takes in proton
(b) its atoms are removed
(c) it gives away electrons
(d) it gives away positive charge

Ans: c

16. Two lamps 100 W and 40 W are connected in series across 230 V (alternating). Which of the following statement is correct ?
(a) 100 W lamp will glow brighter
(b) 40 W lamp will glow brighter
(c) Both lamps will glow equally bright
(d) 40 W lamp will fuse

Ans: b

17. When electric current passes through a bucket full of water, lot of bubbling is observed. This suggests that the type of supply is
(a) A.C.
(b) D.C.
(c) any of above two
(d) none of the above

Ans: b

18. For testing appliances, the wattage of test lamp should be
(a) very low
(b) low
(c) high
(d) any value

Ans: c

19. Sparking occurs when a load is switched off because the circuit has high
(a) resistance
(b) inductance
(c) capacitance
(d) impedance

Ans: b

20. A substance whose molecules consist of dissimilar atoms is called
(a) semi-conductor
(b) super-conductor
(c) compound
(d) insulator

Ans: c

21. International ohm is defined in terms of the resistance of
(a) a column of mercury
(b) a cube of carbon
(c) a cube of copper
(d) the unit length of wire

Ans: a

22. The condition for the validity under Ohm’s law is that
(a) resistance must be uniform
(b) current should be proportional to the size of the resistance
(c) resistance must be wire wound type
(d) temperature at positive end should be more than the temperature at negative end

Ans: a

23. A rheostat differs from potentiometer in the respect that it
(a) has lower wattage rating
(b) has higher wattage rating
(c) has large number of turns
(d) offers large number of tapping

Ans: b

24. Voltage dependent resistors are usually made from
(a) charcoal
(b) silicon carbide
(c) nichrome
(d) graphite

Ans: c

25. Voltage dependent resistors are used
(a) for inductive circuits
(6) to supress surges
(c) as heating elements
(d) as current stabilizers

Ans: b

26. Nichrome wire is an alloy of
(c) nickel and chromium
(d) copper and silver

Ans: c

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#MCQ on electrical engineering
#current electricity mcq
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#### 1 comment:

1. very usefull