Ohm's Law Multiple choice Question (Electrical Mcqs) and Answer Part 1
Electrical Engineering Objective Question and Answer
1- Resistivity of wire depends upon
(A) Length
(B) Material
(C)Cross sectional Area
(D) None of above
Answer: (B)
2- When n resistance each of value r are connected in parallel, then resultant resistance is x, when these n resistance are connected in series, total resistance is
(A) nx
(B) rnx
(C) x/n
(D) n^2 * x
Answer: (D)
3- Resistance of a wire is R ohms, The wire is stretched to doubled its length, then its resistance in ohms is
(A) r/2
(B) 4r
(C) 2r
(D) r/4
Answer: (B)
4- Kirchhoff's 2nd law is based on law of conservation of energy
(A) charge
(B) Energy
(C) momentum
(D) mass
Answer: (B)
5- The diameter of the nucleus of an atom is of order of
(A) 10^-31 m
(B) 10^-25 m
(C) 10^-21 m
(D) 10^-14 m
Answer: (D)
6- The mass of proton is roughly how many times the mass of an electron ?
(A) 184,000
(B) 184,00
(C) 1840
(D) 184
Answer: (C)
7- The charge on an electron is known to be 1.6 x 10^-19 coulomb. In a circuit , the current flowing is 1 A. how many electrons will flowing through the circuit in a second?
(A) 1.6 x 10^19
(B) 1.6 x 10^-19
(C) 0.625 x 10^19
(D) 0.625 x 10^12
Answer: (C)
8- Two bulbs marked 200 watt-250 volts and 100 watt -250 volts are joined in series to 250 volts supply. Power consumed in circuit is
(A) 33 Watt
(B) 67 Watt
(C) 100 Watt
(D) 300 Watt
Answer: (B)
9- Ampere second could be the unit of
(A) Power
(B) Conductance
(C) energy
(D) Charge
Answer: (D)
10- Which of the following is not same as watt?
(A) joule/sec
(B) Amperes/volt
(C) Amperes X Volt
(D) (Amperes)^2 x Ohm
Answer: (B)
11- One kilo hour of electrical energy is the same as
(A) 36 x 10^15 watts
(B)36 x 10^15 ergs
(C) 36 x 10^15 joules
(D) 0.625 x 10^12 B.T.U
Answer: (C)
12- An electric current of 5 A is same as
(A) 5 J/C
(B) 5 V/C
(C) 5 C/Sec
(D) 5 W/Sec
Answer: (C)
13- An electron of mass m Kg and having a charge of e columns travel from rest through a potential difference of V volts. Its kinetic energy will be
(A) eV Volts
(B) meV Joules
(C) me/V joules
(D) V/me Joules
Answer: (A)
14- The value of following is given be
100 Kilo ampere x micro ampere /100 milli ampere x 10 ampere
(A) 0.001 ampere
(B) 0.1 ampere
(C) 1 ampere
(D) 10 A
Answer: (B)
15- A circuit contain two unequal resistances in parallel
(A) current is same in both
(B) large current flows in large resistor
(C) potential difference across each is same
(D) smaller resistance has smaller conductance
Answer: (C)
16- conductance is expressed in terms of
(A) ohm/m
(B) m/ohm
(C) mho/m
(D) mho
Answer: (D)
17- Which of the following could be the value of resistivity of copper ?
(A) 1.7 x 10^-8 Ohm-cm
(B) 1.7 x 10^-6 Ohm-cm
(C) 1.6 x 10^-5 Ohm-cm
(D) 1.7 x 10^-4 Ohm-cm
Answer: (B)
18- A copper wire of length l and diameter d has potential difference V applied at its two ends. The drift velocity is Vd. If the diameter of wire is made d/3, then drift velocity becomes.
(A) 9 Vd
(B) Vd/9
(C) Vd/3
(D) Vd
Answer: (D)
19- Two resistances R1 and R2 give combined resistances of 4.5 ohms when in series and 1 ohm when in Parallel.The resistances are
(A) 3 Ohms and 6 ohms
(B) 3 Ohms and 9 Ohms
(C) 1.5 Ohms and 3 Ohms
(D) 1.5 Ohms and 0.5 Ohms
Answer: (C)
20- We have three resistances of values 2 ohms, 3 ohms, and 6 ohms. Which of the following combination will give an effective resistance of 4 Ohms.
(A) All the resistances are in parallel
(B) 2 resistances in series with parallel combination of 3 ohm and 6 ohm resistances
(C) 3 ohm resistance in series with parallel combination of 2 ohm and 3 ohm resistance
(D) 6 ohm resistance in series with parallel combination of 2 ohm and 3 ohm resistance
Answer: (B)
