Ohm's Law Multiple choice Question (Electrical Mcqs) and Answer Part 6
Electrical Engineering Objective Question and Answer
101-
The resistance of a 1 meter length of 18 gauge copper wire is k ohm. The resistance of one meter length of 24 gauge copper wire will be
(A) k/2 ohm
(B) 18/24 k ohm
(C) k ohm
(D) more than k ohm
Answer: (D)
102- In the circuit shown , the resistance R has a value that depends on the current. specially , R is 20 ohms when the current I is zero, and the amount of increase in resistance is numerically equal to one-half of the current. what is the value of current in the circuit ?
(A) 8.33 A
(B) 10 A
(C) 12.5 A
(D) 50 A
Answer: (B)
103- How much the resistance of a conductor will increase , if its length and diameter is increased by 3 times ,
(A) 66*2/3 %
(B) 33 *1/3 %
(C) -66 * 2/3 %
(D) -33 *1/3%
Answer: (C)
104- which one will be true for an incandescent bulb, if its resistance changes with the change of applied voltage
(A) The internal inductance of the bulb causes this change
(B)The bulb is said to have a low ionization potential
(C) The bulb has constant resistance
(D) This bulb is non-linear device
Answer: (D)
105- The method which can be used for absolute measurement of resistance
(A) Ohm's law method
(B) Wheatstone bridge method
(C) Raleigh method
(D) Lorentz method
Answer: (D)
106- Two 1 kilo ohm, 1/2 watt resistor are connected in series, Their combined resistance value and Wattage will be
(A) 2 kilo ohm , 1/2 watt
(B) 2 kilo ohm , 1 watt
(C) 2 kilo ohm , 2 watt
(D) 1 kilo ohm , 1/2 watt
Answer: (B)
107- The resistance of 100 W , 200 V lamp is
(A) 100 ohm
(B) 200 ohm
(C) 400 ohm
(D) 1600 ohm
Answer: (C)
108-A cylindrical wire is compressed in length by 10%, The percentage decrease in the resistance will be
(A) 16%
(B) 19%
(C) 20%
(D) 25%
Answer: (B)
109- Three resistances of 6 ohm each are connected as shown in fig 15. The equivalent resistances between X1 and X2 is
(A) 2 ohm
(B) 4 ohm
(C) 8 ohm
(D) 12 ohm
Answer: (A)
110- The unit of conductance is
(A) per ohm
(B) ohm/m
(C) mho/m
(D) mho
Answer: (D)
111- Ohm's law is not applicable in all the following cases except
(A) Electrolysis
(B) Arc lamps
(C) Insulators
(D) Vacuum radio valves
Answer: (C)
112- In which of the following circuits will the voltage source produce the most current ?
(A) 10 V across a 10 ohm
(B)10 V across two 10 ohm resistance in series
(C) 10 v across two 10 ohm
(D) 1000 V across mega ohm resistance
Answer: (C)
113- A piece of silver wire has a resistance of 1 ohm. A manganin wire has specific resistance 30 times that of silver. The resistance of a manganin wire of one fourth length and one third diameter will be
(A) 6/5 ohm
(B) 1 ohm
(C) 67.5 ohms
(D) 86.75 ohm
Answer: (C)
114- A cube of material of side 1 cm has a resistance of 0.002 ohm between its opposite faces. if the same volume of the material has length of 8 cm and a uniform cross-section, the resistance of this length will be
(A) 0.032 ohm
(B) 0.064 ohm
(C) 0.096 ohm
(D) 0.128 ohm
Answer: (D)
115- The unit of conductivity is
(A) mho/meter
(B)mho/sq.m
(C) ohm/meter
(D) ohm/sq.m
Answer: (A)
116- For the circuit shown in Fig. 16 the meter will read
(A) 1 A
(B) 5 A
(C) 10 A
(D) 25 A
Answer: (C)
117- For the circuit shown in Fig. 17 , the reading in the ammeter A will be
(A) 2 A
(B) 0.5 A
(C) 0.4 A
(D) 0.2 A
Answer: (C)
118- According to Joule law heat produced by a current I while in flowing through a material of resistance R for a length of time T , is proportional to
(A) T only
(B) (RT only )
(C) (IRT)
(D) I^2 RT
Answer: (D)
119- In the Color code for resistances black color represents the number
(A) 0
(B)1
(C) 2
(D) 3
Answer: (A)
120- White color represents the which number in color code.
(A) 0
(B) 1
(C) 2
(D) 3
Answer: (A)
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