Subject : Basic Electricity
Instruction:
Time limit for the exam: 25 Minutes
Total number of questions : 30 Q
Each question carry 1 mark, no negative marks.
DO NOT refresh the page.
All the best by BSNL ACADEMY
If U Like Our Test series than Share with your friends and Rate Our Tests.
The resistance of a conductor of diameter d and length l is R Ω. If the diameter of the conductor is halved and its length is doubled, the resistance will be
Answer
R Ω
2R Ω
4R Ω
8R Ω
Question 2
Question
How many coulombs of charge flow through a circuit carrying a current of 10 A in 1 minute?
Answer
10
60
600
1200
Question 3
Question
Instantaneous power in inductor is proportional to the
Answer
product of the instantaneous current and rate of change of current.
square of instantaneous current.
square of the rate of change of current.
temperature of the inductor.
Question 4
Question
If P is the power of a star connected system then what will be power of an equivalent delta connected system?
Answer
P
3P
P/3
None of the above
Question 5
Question
Power dissipation in ideal inductor is
Answer
Maximum
Minimum
Zero
A finite value
Question 6
Question
Inductor does not allow the sudden change of
Answer
current
voltage
power
None of the above
Question 7
Question
Which of the following has no units?
Answer
Permeability
Moment of a magnet
Magnetic susceptibility
Permittivity
Question 8
Question
Which of the following defined the average value ?
Answer
Voltage
Heating effect
Current
Charge transfer
Question 9
Question
If a pure inductor is connected across the ac source, the average power taken by the inductor is
Answer
A few watt
100 watt
zero watt
Maximum power
Question 10
Question
In RLC series circuit R = 2Ω, L = 2mH and C = 1μF. Find the time constant of the circuit?
Answer
1 μsec
2 msec
2 μsec
4 msec
Question 11
Question
The right hand rule for determining the direction of the induced EMF was introduced by
Answer
Faraday
Lenz
Fleming
Maxwell
Question 12
Question
Whenever the magnetic flux changes with respect to an electric conductor or a coil, an EMF is induced in the conductor is Faraday’s
Answer
first law
second law
third law
fourth law
Question 13
Question
Which of the following represents ohms law
Answer
V = RI
J = σE
I = GV
All of the above
Question 14
Question
In the left hand rule, forefinger always represents
Answer
voltage.
current.
magnetic field.
direction of force on the conductor.
Question 15
Question
Cork Screw rule is used to find
Answer
direction of current.
direction of magnetic field.
direction of electric field.
direction of emf.
Question 16
Question
Biot-Savarts law states the relation between magnetic intensity and
Answer
filament current only.
surface current only.
volume current only.
(A), (B), and (C) are all correct.
Question 17
Question
The drawback of Daltons atomic structure is that, it says
Answer
the atoms can neither be created nor be destroyed.
unique nature of atom.
most of the volume of an atom is empty space.
none of these.
Question 18
Question
According to Coulomb’s law, the force of attraction or repulsion, between to electrical charges is
Answer
directly proportional to the square of the distance between them.
inversely proportional to the square of the distance between them.
inversely proportional to the distance between them.
directly proportional to the distance between them.
Question 19
Question
Ohm’s law in point from field theory can be expressed as
Answer
J = σE.
V = IR.
J = E / σ.
R = ρ × ( l / A).
Question 20
Question
Coulombs law for the force between electric charges most closely resembles with
Answer
Newtons law of motion.
Law of conservation of energy.
Gausss theorem.
Newtons law of gravitation.
Question 21
Question
The Biot-savarts law is a general modification of
Answer
Kirchhoffs law.
Lenzs law.
Amperes law.
Faradays law.
Question 22
Question
The direction of induced emf can be found by
Answer
Laplaces law.
Kirchhoffs voltage law.
Lenzs law.
Flemings right hand rule.
Question 23
Question
Conductor is constant and field is varying then emf will induce. This principle is called
Answer
virtually induced emf.
dynamically induced emf.
static induced emf.
none of the above.
Question 24
Question
The operation of electric generators and motors depend on the intraction between magnetic field and
Answer
Commutator.
Electric current.
Copper conductors.
Electric fields.
Question 25
Question
The heating time constant of an electrical machine gives an induction of its
Answer
rating.
cooling.
overload capacity.
short time rating.
Question 26
Question
Flemings left hand rule may be applied to an electric generator to find out the direction of
Answer
induced emf.
rotor rotation.
magnetic field.
none of the above.
Question 27
Question
Nodal analysis can be applied for
Answer
planar networks.
non planar networks.
both planner and non planner networks.
neither planner nor non planner networks.
Question 28
Question
KCL works on the principle of which of the following