The distance between the capacitor plates increases two timesa then its capacitance
Increases two times
Increases four times
Decreases two times
Decreases four times
Correct Answer :
C. Decreases two times
Related Questions
What theorem is generally used in the analysis of vacuum tubes?
Superposition theorem
Millman�s theorem
Thevenin�s theorem
Norton�s theorem
The rms value of a triangular or sawtooth waveform is ___ tim value.
In a circuita a passive element is one which
Supplies energy
Receives energy
Both supplies and receives energy
Attenuates signal
What is the complex impedance of a circuit with an absolute resistance of 300 ?
0 + j 300
300 + j 90
0 ± j 300
300 +j 0
If the capacitance of mica capacitor is 5 times the capacitcitora then the relative permittivity of mica is
For greater accuracya the value of phase angle should be determined from
Cos
Tan
Sin
Sec
Points to be considered in choosing a capacitor
Working voltage
Type of dielectric
Capacitance
All of the above
Which of the following is a preferred resistor value?
43a000
54a321
In calculating maximum instantaneous power ___ voltage or current is used.
Peak
Average
Rms
Instantaneous
A capacitor is used to
Block dc current
Pass dc current
Open voltage source
Short the voltage source
If two resistances of 9 and 6 are connected in parallela the total resistance is
If the output resistance of a voltage source is 4 a it internal resistance should be
Infinite
A series RLCcircuit has a ______ power factor at its half-power points
Unity
Leading
Lagging
Either B or C
In a circuita an active element is one which
Supplies energy
Receives energy
Both supplies and receives energy
Amplifies signal
What theorem is usually used in the analysis of transistor circuit?
Superposition theorem
Millman�s theorem
Thevenin�s theorem
Norton�s theorem
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
The ratio between the reactive power and the apparent power of an ac load is called
Quality factor
Power factor
Power ratio
Reactive power
Voltage resonance means
Series resonance
Parallel resonance
Current magnification
Gain magnification
If a certain circuit has a current that is lagging the voltage by 45�a then it displays
Pure inductive reactance
Resistance and capacitance reactance
Resistance and inductive reactance
Pure capacitive reactance
The Q-factor of a series resonant circuit is also known as
Current magnification factor
Voltage magnification factor
Load factor
Leakage factor
The Q-factor of a parallel resonant circuit is also known as
Current magnification factor
Voltage magnification factor
Load factor
Leakage factor
The internal resistance of an ideal current source is
Infinite
Zero
Equal to the load resistance
To be determined
The current is ____ times the maximum current at half-power points of a resonance curve.
Resistor with colored bands in the body
Wire-wound resistor
Carbon-composition resistor
Potentiometer
Rheostat
If a coil has a Q of 10a it means that
The energy stored in the magnetic field of the coil is 10 times the energy wasted in its resistance
The energy wasted in its resistance is 10 times the energy stored in the magnetic field of the coil
It is a low Q coil
It is a high Q coil
In a multiple capacitora the plate area is
Increased
The same
Decreased
Variable
What increases the resistance of wire at high frequencies?
Temperature
Voltage
Skin effect
Insulation
VL= VCin a series RLCcircuit when
The value of the impedance is minimum
The power factor is zero
The current leads the total voltage by 90�
The total voltage is zero
In an ac circuit with inductive reactance ?, the
Phase angle of the circuit is always 45�
Voltage across the inductance must be 90� out o f-phase witht he applied voltage
Current through the inductance lags its induced voltage by 90�
Current through the inductance and voltage across it are180� outof-phase
A term used to express the amount of electrical energy stored in electrostatic field.
Joules
Coulombs
Watts
Electron-volt