A rheostat is a form of
Variable resistor
Variable capacitor
Potentiometer
Thermocouple
Correct Answer :
A. Variable resistor
Related Questions
A rheostat is a form of
Variable resistor
Variable capacitor
Potentiometer
Thermocouple
If two equal resistances connected in series across a certain supply are now connected in parallel across the same supplya the power produced will be _____ that of series connection
One-half
One-fourth
Two times
Four times
The Q-factor of a parallel resonant circuit is also known as
Voltage magnification factor
Current magnification factor
Gain magnification factor
Resonance magnification factor
If voltage across the plates of 2 F capacitor is increased by 4 Va then charge on the plates will
Decrease by 2 C
Increase by 2 C
Decrease by 4 C
Increase by 4C
Form its definitiona the unit of electric fielda is the N/C and equivalent unit of is the
V(m)2
V(m)
V/m2
V/m
An electric circuit contains
Passive elements
Active elements
Both active and passive elements
Reactive elements
Which factor does not affect resistance?
Length
Resistivity
Cross-sectional area
Mass
Resistor with colored bands in the body
Wire-wound resistor
Carbon-composition resistor
Potentiometer
Rheostat
What is the value of a carbon composition resistor with the following color code: Browna whitea orangea red
190 ; 10 %
19 k ; 2 %
19 k ; 20 %
1.9 k ; 2 %
Another term for superconductor.
Generic conductor
Ultraconductor
Cryotron
Cryogenic conductor
When two unequal values of resistors are connected in parallel across a dc sourcea greater current flows through the
Higher resistance
Lower resistance
Higher wattage resistance
Lower wattage resistance
If two resistances of 9 and 6 are connected in parallela the total resistance is
What maximum voltage can be applied across the capacitor of time?
Working voltage
Surge voltage
Stray voltage
Peak voltage
What is the specific resistance of a pure germanium?
55 -cm
55 -m
55 -mm
55 k -m
An impedance given by 90 -45� is a/an ___ impedance.
Inductive
Conductive
Resistive
Capacitive
The second strip of an electronic resistor color-code represents
The multiplier
The second digit of the value
The temperature
The tolerance
Loop currents should be assumed to flow in which direction
Straight
Clockwise
Counter-clockwise
Either B or C arbitrarily selected
If the output resistance of a voltage source is 4 a it internal resistance should be
Infinite
Under the conditions of maximum power transfera a voltage source is delivering a power of 15 W to the load. What is the power generated by the source?
60 W
30 W
15 W
4 W
A capacitance of 0.05 F equals
0.05 x 106F
0.05 x 10-6F
0.05 x 10-12F
0.05 x 1012F
Conventional flow assumes charges flow from
Positive to negative
Positive to positive
Negative to positive
Negative to negative
For a linear circuita ___ voltage or current is used to calculate average power.
Rms
Peak
Average
Instantaneous
For a triangular and sawtooth waveform the rms voltage or current equals
0.707times peak value
0.577 times peak value
0.577times average value
0.707times rms value
An open inductor has
Zero resistance and infinite inductance
Infinite resistance and zero inductance
Infinite resistance and infinite inductance
Zero resistance and zero inductance
The charging of a capacitor through a resistance follows what law?
Linear law
Hyperbolic law
Inverse-square law
Exponential law
The capacitance of a capacitor is ___ relative permittivity.
Directly proportional to
Inversely proportional to
Equal to
Inversely proportional to the square of
What is the peak factor of a triangular wave?
What is the rms value of a square wave?
Equals its peak value
Equals its peak-to-peak value
Peak divided by square root of two
Peak divided by pi
What determines the direction of induced emf in a conductor or coil?
Cork screw rule
Fleming�s left hand rule
Ampere�s circuital law
Fleming�s right hand rule
The presence of an electric current is made known by
Electric shock
Effects produced
Magnetic shock
Flashing