A capacitor is basically constructed of
Two conductors separated by a dielectric
Two dielectric separated by a conductor
Conductors and dielectric
Conductors and semiconductors
Correct Answer :
A. Two conductors separated by a dielectric
Related Questions
Series resonance occurs when
XL= XC
XL= R
Z = R
Both A and C
What is the most common non-sinusoidal waveform?
Square wave
Triangular wave
Trapezoidal wave
Sawtooth wave
The value of temperature coefficient ( ) is dependent upon
The nature of material and temperature
The length of material
The cross-sectional area of the material
The volume of the material
What is the total resistance of a two equal valued resistors in series?
The difference of both
The product of both
Twice as one
The sum of their reciprocals
The electric field strength between capacitor plates has a unit
Volts per meter
Volts per mil
Amperes per meter
Amperes per mil
Which of the following combination of length and cross-sectional area will give a certain volume of copper the least resistance?
2L and1/2 A
Does not matter because the volume of copper remains the same
L and A
½ L and 2 A
The reason why alternating current can induce voltage is
It has high peak value
It has a stronger magnetic field than direct current
It has a constant magnetic field
It has a varying magnetic field
Refers specifically to steady state values of quantities in ac circuits which are complex numbers.
Domain
Scalar quantity
Vector quantity
Phasor quantity
What is the hot resistance of a 100 Wa 220 V incandescent lamp?
Why are inductance and capacitance not relevant in a dc circuit?
Because it is a simple circuit
Because dc circuits require only resistance as load
Because they do not exist in a dc circuit
Because frequency of dc is zero
In a series RLCcircuit
The current lags VLby 90�
The current leads VLby 90�
XL leads Xcby 90�
Z = jXL at resonance
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
The power factor of a certain circuit in which the voltage lags behind the current is 80 %. To increase the power to 100 %a it is necessary to add ___ to the circuit.
Inductance
Capacitance
Resistance
Impedance
In an ac circuit with a resistive branch and an inductive branch in parallela the
Voltage across the inductance leads the voltage across the resistance by 90°
Resistive branch current is 90° out of phase with the inductive branch current
Resistive and inductive branch currents have the same phase
Resistive and inductive branch currents are 180° outof-phase
The open-circuit voltage at the terminal of load RL is 60V. Under the condition of maximum power transfera the load voltage will be
60 V
15 V
20 V
30 V
Voltage resonance means
Series resonance
Parallel resonance
Current magnification
Gain magnification
A law which states that when a constant electromotive force is applied to a circuit consisting of a resistor and capacitor connected in seriesa the time taken for the potential on the plates of the capacitor to rise to any given fraction of its final value depends only on the product of capacitance and resistance.
Child�s law
CR law
Coulomb�s law
Debye T3 law
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
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
When the power factor of a circuit is zeroa
Power absorbed is maximum
Power absorbed is minimum
Power absorbed is zero
The impedance is minimum
In an ac circuita the power dissipated as heat depends on
Impedance
Capacitive reactance
Resistance
Inductive reactance
Which of the following is not a factor affecting dielectric strength?
Mass
Moisture content
Temperature
Thickness
The reactance curve is a plot of frequency versus _____ for a series RLCcircuit
Current
Voltage
Gain
Impedance
When two coils of identical reactance are in parallel without mutual inductancea the reactance of the combination is ___ the reactance of each coil.
One half
Twice
Four times
One fourth
The ratio of W/VA in an ac circuit means
Power factor
Reactive factor
Quality factor
Load factor
Which of the following is a preferred resistor value?
43a000
54a321
A lead conductor has a resistance of 25 at 0 �C. Determine its resistance at -30 �C
A gang capacitor is a variable capacitor in which capacitance is varied by changing the
Dielectric
Number of plates
Plate area
Distance between plates
In an ac wavea 30 degrees of phase is ___ of a cycle.
½
A tank circuit is a
Parallel LC circuit
Series LCcircuit
A resonant circuit
A non-resonant circuit