WorksheetsEE Objective
Total questions: 40
Worksheet time: 20mins
The maximum number of electrons that can be accommodated in the last orbit of an atom is
4
8
2
6
The electrons in the last orbit of an atom are called ___ electrons
free
bound
valence
thermionic
if the number of valence electrons of an atom is less than 4, the substance is usually __
an insulator
a semi-conductor
a conductor
none of these
if the number of valence electrons of an atom is more than 4, the substance is usually
an insulator
a conductor
a semi-conductor
none of the above
if the number of valence electrons of an atom is exactly 4, then the substance is usually ___
an insulator
a conductor
a semi-conductor
None of these
an electron has a negative charge of ___ coulomb.
9.8x10^-22
9.8x10^-19
1.6x10^-22
1.6x10^-19
Electric flow current in a wire is the flow of ___
bound electrons
atoms
free electrons
valence electrons
Prevent electric current to flow and at the same time electric energy is converted into heat energy.
capacitance
inductance
impedance
resistance
Conductors have ___ temperature coefficient of resistance
negative
positive
zero
none of these
Insulators and semi-conductors have ___ temperature coefficient of resistance
positive
zero
negative
none of these
The temperature coefficient of resistance of a conductor ___ with the rise in temperature
remains the same
increases
approaches zero
decreases
The value of the temperature coefficient of resistance of a conductor depends upon ___.
length of the material
volume of the material
cross-sectional area of the material
nature of the material and temperature
An alloy of 40% nickel and 60% copper used for making rheostat and wire-wound resistor is called ___.
eureka
alnico
nichrome
none of these
Out of the following, select the best conductor of electricity.
graphite
porcelain
china clay
none of these
Which of the following statement is correct?
Resistance does not play an important role in electrical engineering
The resistance of a wire does not depend upon its material
The resistance of most of the materials is independent of the temperature
The resistance of the conductor is the hindrance by which the conductor opposes the flow of the current
Resistance of a conductor increases when
its length increases
its area increases
both area and length increases
specific resistance is kept constant
The specific resistance depends upon ___
the area and length of the conductor
the material of the conductor and its area
the nature of the material of the conductor
the area of the conductor
The resistance of a conductor, when it's temperature is increased ___
remains constant
varies
increases
decreases
When current flows through a conductor, heat is produced because ___.
heat is directly proportional to the square
of electrons collision
of interatomic collision
of joules law
Heating effect of electric current has undesirable side effects in ___.
electric oven
immersion heater
electric iron
vacuum cleaner
The resistance if carbon when its temperature is decreased ___
increases
remains the same
decreases
increases enormously
The curve representing ohms law is ___.
a parabola
sine function
linear
a hyperbola
The condition in ohms law is that ___
a ratio V/I should be constant
current should be proportional to voltage
temperature should vary
temperature should remain constant
Ohms law does not apply to ___.
rectifying devices
electrolytes
semi-conductors
thermionic valves
Ohms law is applicable to ___.
electric arc
gas discharge lamps
rectifying devices
none of these
The presence of an electric current is made known by.
flashing
cracking
effects produced
electric shock
Ohms can be applied with certain reservation to ___.
rectifying devices
electrolytes
semi-conductors
thermionic valves
Voltage applied across a circuit, acts as
mass of electrons
negative ions
a force
none of these
In a series circuit, the current is
constant
proportional to the resistance
different in different resistors
always zero
Resistors commonly used in power circuits are ____.
carbon resistors
etched circuit resistors
wire wound resistors
none of these
Electrical appliances are not connected in series because ___.
series circuit is complicated
appliance have different current ratings
power loss is more
none of these
Electrical appliance are connected in parallel because
it is a simple circuit
it results in reduced power loss
it makes the operation of the appliance independent of each other
less current is required
Cells are connected in series when ___ is required
high voltage
high current
high power
none of these
Cells are connected in parallel when ___ is required
low voltage
high voltage
high power
high current
A material used in making heating elements
carbon
eureka
tungsten
nichrome
In a balanced 3 phase wye connected circuit the line voltage are equal
and so are the line currents
to the phase voltage
but the line currents are unequal
but the phase voltage are unequal
The type of ac distribution system commonly used to supply both light and power is the
open delta system
three phase delta system
three phase wye system with neutral wire
three phase wye system without neutral
The phase displacement between phasors in polyphase system is always
90 degrees
120 degrees
180 degrees
360 degrees divided by the number of phase
In a balanced 3 phase, wye connected system line voltage is
the phasor difference of the two phase voltage
the phasor sum of two phase voltages
0.707 times the phase voltage
1.414 times the phase voltage
In a wye connected system the line current is
0.707 times the phase current
1.732 times the phase current
phasor sum of the two phase currents
equal phase to the phase current
