1. Which method can be used for absolute measurement of resistors?
(A) Lorentz method
(B) Rayleigh method
(C) Ohm’s law method
(D) Wheatstone bridge method
2. Three 6 ohm resistors are connected to form a triangle. What is the resistance between any two corners?
(A) 3/2 Ohms
(B) 6 Ohms
(C) 4 Ohms
(D) 8/3 Ohms
Answer: (C)
3. Ohm's law does not apply.
(A) semi-conductor
(B) D.C circuit
(C) small resistors
(D) high currents
Answer: (A)
4.
Two copper conductors have the same length. The cross-sectional area of
one conductor is four times that of another. If the conductor with a
small cross-sectional area has a resistance of 40 ohms, the resistance
of the other conductors will be
(A) 160 ohm
(B) 80 ohms
(C) 20 ohms
(D) 10 ohm
Answer: (D)
5. Temperature coefficient of resistance is expressed in terms of
(A) Ohm / ° C
(B) mhos/ohm ° C
(C) ohm/ohm ° C
(D) mhos / ° C
Answer: (A)
6. The resistance of the filament of a hot bulb is greater than the filament resistance of a cold bulb because of the temperature co-efficient of the filament is.
(A) zero
(B) negative
(C) positive
(D) about 2 ohms per degree
Answer: (C)
7. Heat produced in a conductor is passed by an electric current.
(A) reaction
(B) capacitance
(C) impedance
(D) resistance
Answer: (A)
8. Insulation is provided on a current carrying conductor.
(A) To prevent leakage of current
(B) to prevent shock
(C) Both of the above factors
(D) None of the above factors
Answer: (C)
9. The thickness of insulation provided on the conductor depends
(A) the magnitude of the voltage on the conductor
(B) the magnitude of the current flowing through it
(C) Both (A) and (B)
(D) None of the above
Answer: (A)
10. Which of the following materials has the lowest resistivity?
(A) zinc
(B) lead
(C) mercury
(D) copper
Answer: D
11. Ohm's Law does not apply
(A) Vacuum tube
(B) carbon resistors
(C) High voltage circuit
(D) none of these
Answer: (A)
12. Who is the best conductor of electricity?
(A) Iron
(B) Silver
(C) copper
(D) Carbon
Ans: (B)
13. For which of the following can the ampere second unit be?
(A) Reluctance
(B) Charge
(C) Power
(D) Energy
Ans: (B)
14. All of which are equivalent to watts except for the following
(A) (ampere) ohm
(B) Joules / sec
(C) ampere x volt
(D) ampere / volt
Ans: (D)
15. 10 ohms, the resistance with a rating of 10 w will be
(A) metallic resistor
(B) carbon resistor
(C) wire wound resistor
(D) variable resistor
Answer: (C)
16. Which of the following is not negative temperature co-efficient?
(A) aluminum
(B) paper
(C) rubber
(D) Mica
Answer: (A)
17. Varistors are
(A) Insulator
(B) non-linear resistors
(C) carbon resistors
(D) Resistant with zero temperature coefficient
Ans: (B)
18. Insulating material has function
(A) Preventing short circuit between wiring operations
(B) Stopping an open circuit between voltage source and load
(C) Conducting very large currents
(D) Storage of very high currents
Ans: (B)
19. The rating of a fuse wire is always expressed
(A) ampere-hour
(B) ampere-volt
(C) kWh
(D) Ampere
Ans: (D)
20. Ion has a minimum charge
(A) equal to atomic number of atoms
(B) equal to the charge of an electron
(C) One atom (#) equal to the charge of the number of electrons in zero
(D) Ampere
Ans: (B)
21. In a series circuit with unequal resistors
(A) The highest resistance has the highest current through it.
(B) The lowest resistance has the highest voltage drop
(C) Lowest resistance has highest current
(D) The highest resistance has the highest voltage drop
Ans: (D)
22. What is the filament of electric bulb made of?
(A) Carbon
(B) aluminum
(C) tungsten
(D) Nickel
Answer: (C)
23. When a current of 2amp flows in a 3ohms resistance, power will be expended
(A) 2 watts
(B) 4 watts
(C) 6 watts
(D) 12 watts
Answer: (D)
24. Which of the following statements is true?
(A) A galvanometer is a voltmeter with low resistance in parallel
(B) A galvanometer with high resistance in parallel is a voltmeter
(C) A galvanometer with low resistance in series is an ammeter
(D) A galvanometer with high resistance in series is an ammeter
Answer: (C)
25. The resistance of a few meters of wire conductors in a closed electrical circuit is
(A) practically zero
(B) less
(C) high
(D) is too much
Answer: (A)
26. If the main line is opened in a parallel circuit, the current
(A) grows in the branch of lowest resistance
(B) grows in each branch
(C) All branches have zero
(D) is zero at the highest resistance branch
Answer: (C)
27. If a wire conductor of 0.2 ohm resistance doubles in length, its resistance becomes
(A) 0.4 ohm
(B) 0.6 ohm
(C) 0.8 ohm
(D) 1.0 ohm
Answer: (A)
28. Three 60 W, 60 V bulbs are connected in parallel to the power line. If a bulb burns
(A) There will be heavy current in the main line
(B) The remaining two bulbs will not light
(C) All three bulbs will light
(D) The other two bulbs will light
Ans: (D)
29. Four 40 watt bulbs are connected in series with the battery, which of the following statements is correct?
(A) Current will flow through each bulb
(B) The voltage in each bulb is not the same
(C) Electrical dissipation is not same in every bulb
(D) None of the above
Answer: (A)
30. The resistance of a closed switch is
(A) zero
(B) about 50 ohms
(C) around 500 ohms
(D) Infinite
Answer: (A)
31. Why a glass rod gets charged when rubbed with silk cloth
(A) It takes in protons
(B) its atoms are removed
(C) It removes electrons
(D) It gives positive charge
Answer: (C)
32. 122. The magnitude of current in AC and DC circuits can be reduced by
(A) reactor
(B) capacitor
(C) inductor
(D) register
Ans: (D)
33. It becomes more difficult to remove
(A) An electron from the orbit
(B) First electron from orbit
(C) Second electron from orbit
(D) Third electron from orbit
Ans: (D)
34. When a branch of a parallel circuit is opened, what will be the effect on the current?
(A) will decrease
(B) Increase
(C) decrease
(D) becomes zero
Answer: (C)
35. When more than one lamp is turned on in a lamp load, what will be the effect on the total resistance
(A) increases
(B) decreases
(C) remains the same
(D) None of the above
Ans: (B)
36. 230v AC of two lamps 100w and 40w. If connected with supply in series
Which of the following statements is correct?
(A) 100 watt lamp will glow more
(B) 40 watt lamp will glow more
(C) Both lamps will shine equally
(D) 40 W lamp will fuse
Ans: (B)
37. The resistance of 100 W, 220 V lamps will be
(A) 4.84 ohms
(B) 48.4 ohm
(C) 484 ohms
(D) 4840 ohm
Answer: (C)
38. D.C. In the case of
(A) The magnitude and the direction of current are constant
(B) The magnitude and direction of current changes over time
(C) the magnitude of the current changes over time
(D) the magnitude of the current remains constant
Answer: (A)
39.
When electric current passes through a bucket filled with water, a lot
of bubbling is seen. This shows what is the type of supply
(A) A.C.
(B) D.C.
(C) Either of the above
(D) None of the above
Ans: (B)
40. Resistance of carbon filament lamps when supply voltage increases.
(A) increases
(B) decreases
(C) remains the same
(D) None of the above
Ans: (B)
41. Which of the following quantities remain the same in all parts of a series circuit?
(A) voltage
(B) current
(C) power
(D) resistance
Ans: (B)
42.
A 40w bulb is connected in series with a room heater. If the 40w bulb
is replaced with a 100w bulb now, the heater output will be
(A) decrease
(B) increase
(C) be equal
(D) the heater will burn
Ans: (B)
43.
In an electric kettle, the water boils in 10 minutes, it is necessary
to boil the boiler in 15 minutes, what changes will have to be made if
the supply voltage is kept the same
(A) The length of the heating element should be reduced
(B) The length of the heating element should be increased
(C) Heating element length has no effect on heating on water
(D) None of the above
Answer: (A)
44. Electric filament of a bulb can work on which supply
(A) D.C. supply only
(B) A.C. supply only
(C) Battery supply only
(d) All of the above
Ans: (d)
45. What is the effect of increasing the applied voltage on the resistance of tungsten lamps
(A) decreases
(B) increases
(C) remains the same
(D) None of the above
Ans: (B)
46. Electric current passing through the circuit is generated
(A) magnetic effect
(B) luminous effect
(C) Thermal effect
(D) Chemical effects
Answer: (C)
47. The resistance of a material always decreases if
(A) The temperature of the material decreases
(B) The temperature of the material increases
(C) The number of available free electrons increases
(D) None of the above is correct
Answer: (C)
48. If the efficiency of a machine should be reduced for more?
(A) input power
(B) losses
(C) True component of power
(D) kWh consumed
Ans: (B)
49. When electric current passes through a metallic conductor, its temperature increases. this is due to
(A) collision between conduction electrons and atoms
(B) release of conduction electrons from parent atoms
(C) mutual collision between metal atoms
(D) Mutual collision between the conduction of electrons
Answer: (A)
50. If two bulbs are of 200 W and 500 W of 250 V, what will be their resistance ratio?
(A) 4: 25
(B) 25: 4
(C) 2: 5
(D) 5: 2
Answer: (C)