A trimmer is a variable capacitor in which capacitance is varied by changing the
Number of plates
Dielectric
Distance between plates
Plate area
Correct Answer :
C. Distance between plates
Related Questions
What value of R is needed with a 0.05 F Cfor an RCtime constant of 0.02 s?
400 M
400 G
400 k
Which statement is true about a passive circuit?
A circuit with neither a source of current nor a source of potential difference
A circuit with a voltage source
A circuit with a current source
A circuit with only resistance as a load
The second strip of an electronic resistor color-code represents
The multiplier
The second digit of the value
The temperature
The tolerance
What capacitance exists not through design but simply because two conducting surfaces are relatively close to each other?
Surge
Stray
Natural
Normal
In a series RLCcircuit
Increasing the frequency decreases the resistance
Increasing the frequency increases the resistance
Both XLand XCchange as frequency changes
Impedance will always decrease
A resistor wound with a wire doubled back on itself to reduce the inductance.
Bifilar resistor
Wire-wound resistor
Anti-inductive resistor
Bleeder resistor
What is the form factor of a triangular wave?
Which of the following is not considered a physical factor affecting resistance?
Length
Material type
Temperature
Cross-sectional
The power factor of a circuit is equal to
RZ
XC/Z
XL/Z
R/Z
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
What rating of a resistor determines its ability to absorb heat?
Wattage
Ohmic
Current
Voltage
Another term of the quality factor of the resonant circuit.
Figure of merit
Figure of demerit
Noise factor
Noise figure
For a parallel ACcircuita ___ is used as a reference phasor.
Voltage
Power
Current
Resistance
Which of the statements below is not true?
Current source is an active element
Resistor is a linear element
Voltage source is a passive element
Diode is a non-linear element
If the output resistance of a voltage source is 4 a it internal resistance should be
Infinite
An inductive circuit of resistance 16.5 and inductance of 0.14 H takes a current of 25 ?. if the frequency is 50 Hza find the supply voltage.
1501 V
1174V
1877V
991 V
What is expected when two 20 k a 1 watt resistor in parallel are use instead of one 10 k a 1 watt?
Provides higher current
Provides less power
Provides more power
Provides wider tolerance
Which of the following is the statement of Ohm�s law?
Electric current is directly proportional to both voltage and resistance
Electric current varies directly as the voltage and inversely as the resistance
Electrical power is directly proportional to the resistance and inversely as the current squared
Electrical power is directly proportional to both voltage squared and the resistance
Another term for superconductor.
Generic conductor
Ultraconductor
Cryotron
Cryogenic conductor
The usual load of a dc circuit is a/an
Resistor
Capacitor
Inductor
Both inductor and capacitor
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
Loop currents should be assumed to flow in which direction
Straight
Clockwise
Counter-clockwise
Either B or C arbitrarily selected
At parallel resonancea the currents flowing through L and C are
Infinite
Zero
Unequal
Equal
If an emf in circuit A produces a current in circuit Ba then the same emf in circuit Bproduces the same current in circuit ? this theorem is known as
Maximum power transfer theorem
Millman�s theorem
Reciprocity theorem
Norton�s theorem
Series resonance occurs when
XL= XC
XL= R
Z = R
Both A and C
What is the time constant for L of 240 mH in series with R of 20 ?
12 ms
4.8 s
83.3 s
12 s
In a complex resistance-reactance planea XLis represented
By an axis opposite the R axis
By an axis perpendicular to the XC axis
By an axis opposite the XCaxis
By an axis parallel to the R axis
In an ac circuit with XL and R in seriesa the
Voltages across R and XL are in phase
Voltage across R lags the voltage across XLby 90°
Voltages across R and XL are 180° outof-phase
Voltage across R leads the voltage across XLby 90°
The wavelength of an alternating waveform depends upon the ___ of the variation.
Period
Number
Frequency
Amplitude
Leakage resistance in a capacitor results into
Internal heating
Internal bleeding
Shorter useful life
Short-circuiting