When frequency of an ac wave decreasesa the value of XLin a coil
Approaches zero
Gets larger positively
Gets larger negatively
Stays constant
Correct Answer :
A. Approaches zero
Related Questions
Series resonance occurs when
XL= XC
XL= R
Z = R
Both A and C
As applied to a series RLCcircuita bandwidth means
The frequency range for maximum power transfer
The difference between the highest and lowest frequencies of the oscillator
The separation of the half-power points
The frequency at which XL= XC
When capacitors are connected in parallela the total capacitance is
Greater than the largest capacitor
Smaller than the largest capacitor
Smaller than the smallest capacitor
Greater than the smallest capacitor
Which of the following is not considered a physical factor affecting resistance?
Length
Material type
Temperature
Cross-sectional
In a series RLCcircuit
The current lags VLby 90�
The current leads VLby 90�
XL leads Xcby 90�
Z = jXL at resonance
Permeability is otherwise known as
Magnetic conductivity
Magnetic susceptibility
Electric conductivity
Electric susceptibility
An electric circuit contains
Passive elements
Active elements
Both active and passive elements
Reactive elements
For a series ACcircuita ___ is not used as a reference phasor.
Voltage
Impedance
Current
Conductance
The result of rust in electrical (wire) connection is
Inductance
Conductance
Impedance
Resistance
The ratio of the flux density to the electric field intensity in the dielectric is called
Permittivity
Field intensity
Permeability
Elasticity
³Any resistance R in a branch of a network in which a current I is flowing can be replaced by a voltage equal to IR�. This states
Compensation theorem
Reciprocity theorem
Millman�s theorem
Superposition theorem
What is the total capacitance of 10 capacitorsa each of 20 F in series?
200 F
2 F
100 F
0.5 F
For maximum power transfera what is the relation between load resistance RL and internal resistance R of the voltage source?
RL= 2 r
RL= 1.5 r
RL= r
RL= 3 r
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
A three-by-threea series-parallel matrix of resistorsa all having the same ohmic valuea would have a net resistance of
One-third the value of a single resistor
Three times the value of a single resistor
The same value as a single resistor
Nine times the value of a single resistor
Which factor does not affect resistance?
Length
Resistivity
Cross-sectional area
Mass
Metal tin becomes superconductor at approximately
6 K
3.7 K
5 K
4.7K
The charging of a capacitor through a resistance follows what law?
Linear law
Hyperbolic law
Inverse-square law
Exponential law
What is the reading of an ohmmeter for a shorted capacitor?
Zero
Infinity
k
M
Which statement is true?
A series resonant circuit is of high impedance
A parallel resonant circuit is of low impedance
A series resonant circuit is inductive if it operates at a frequency higher than the resonant frequency
A parallel resonant circuit is inductive if it operates at a frequency higher than the resonant frequency
The capacitor opposes any change in voltage across it by
Passing a voltage proportional to the rate of change of current
Acting as a short circuit at time equal to zero
Passing a current proportional to the rate of change of voltage
Acting as a short circuit at time equal to infinity
What is the purpose of a load in an electric circuit?
To increase the circuit current
To decrease the circuit current
To utilize electrical energy
To make the circuit complete
A gang capacitor is a variable capacitor in which capacitance is varied by changing the
Dielectric
Number of plates
Plate area
Distance between plates
Transient period is considered over after
What is the form factor of a triangular wave?
The rms value of a triangular or sawtooth waveform is ___ tim value.
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
A series RL circuit has R of 10 and XL of 5 a its impedance in rectangular form is given by
10 +j 5
10 + j 10
10 ± j 5
10 ± j 10
The power factor of a circuit is equal to
RZ
XC/Z
XL/Z
R/Z
The graph between an alternating quantity and time is called
Sine wave
Curve
Waveform
A plot