If three 9 mH inductors are connected in parallel without mutual inductance then the total i nductance is
3 mH
9 mH
27mH
18 mH
Correct Answer :
A. 3 mH
Related Questions
The Q-factor of a parallel resonant circuit is also known as
Current magnification factor
Voltage magnification factor
Load factor
Leakage factor
At what frequency will the current in a series RLCcircuit reach its maximum value for an applied voltage of 15 V with R = 500 a L = 100 H and C= 0.001 F?
503 kHz
403 kHz
603 kHz
303 kHz
Rationalizing the denominator of a complex number means
Eliminating the j component in the denominator
Adding j component in the denominator
Eliminating the j component in the numerator
Adding j component in the numerator
It is impossible to change the voltage across a capacitor instantlya as this would produce ___ current.
Infinite
Zero
Low
High
Another term of the quality factor of the resonant circuit.
Figure of merit
Figure of demerit
Noise factor
Noise figure
In an inductive coila the rate of rise of current is maximum
Near the final maximum value of current
At midvalue of current
At half-power points
After one time constant
What dielectric is generally employed by a variable capacitor?
Mica
Air
Electrolyte
Ceramic
When voltage is applied across a ceramic dielectric the electrostatic field p roduced is 50 times greater than air dielectric. The dielectric constant of ceramic therefore is
The ratio of W/VA in an ac circuit means
Power factor
Reactive factor
Quality factor
Load factor
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 a multiplate capacitor has 10 platesa each of area 10 cm2a then
10 capacitors will be in parallel
10 capacitors will be in series
9 capacitors will be in parallel
9 capacitors will be in series
Which of the following has negative temperature coefficient?
Carbon
Nickel
Brass
Constantan
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
In a series RLCcircuit
The current lags VLby 90�
The current leads VLby 90�
XL leads Xcby 90�
Z = jXL at resonance
What is a rotating vector whose projection can represent either current or voltage in an ac circuit?
Polar diagram
Scalar quantity
Velocity
Phasor
What is the peak factor for alternating current or voltage varying sinusiodally?
The mutual inductance between two coils is ___ the reluctance of magnetic path.
Directly proportional to
Inversely proportional to
Independent to
Equal to
Which of the following does not generally affect the value of a capacitor?
The dielectric material used
The surface area of the plates
The thickness of the dielectric
The voltage applied to the plate
The Q-factor of a parallel resonant circuit is also known as
Voltage magnification factor
Current magnification factor
Gain magnification factor
Resonance magnification factor
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
The reciprocal of a complex number is
A complex number
A real number
An imaginary number
A whole number
The usual load of a dc circuit is a/an
Resistor
Capacitor
Inductor
Both inductor and capacitor
The ratio between the reactive power and the apparent power of an ac load is called
Quality factor
Power factor
Power ratio
Reactive power
The ratio of the flux density to the electric field intensity in the dielectric is called
Permittivity
Field intensity
Permeability
Elasticity
The average value of a triangular or sawtooth wave is _____ times its peak value.
What is the total capacitance of 10 capacitorsa each of 20 F in series?
200 F
2 F
100 F
0.5 F
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 real current source has
Infinite internal resistance
Zero internal resistance
Large internal resistance
Small internal resistance
What refers to the lowest voltage across any insulator that can cause current flow?
Conduction voltage
Critical voltage
Breakdown voltage
Voltage capacity
The hot resistance of an incandescent lamp is about ___ times its cold resistance.