If the output resistance of a voltage source is 4 a it internal resistance should be
Infinite
Correct Answer :
A.
Related Questions
What is the hot resistance of a 100 Wa 220 V incandescent lamp?
An electric circuit contains
Passive elements
Active elements
Both active and passive elements
Reactive elements
In a circuita an active element is one which
Supplies energy
Receives energy
Both supplies and receives energy
Amplifies signal
Which of the following dielectric materials makes the highest-capacitance capacitor?
Air
Barium-strontium titanite
Mica
Electrolyte
The ratio between the reactive power and the apparent power of an ac load is called
Quality factor
Power factor
Power ratio
Reactive power
A linear circuit is one whose parameters
Change with change in voltage
Change with change in current
Do not change with voltage and current
Change with change in voltage and current
The capacitance of a capacitor is ___ relative permittivity.
Directly proportional to
Inversely proportional to
Equal to
Inversely proportional to the square of
If two complex conjugates are addeda ___ components results.
In-phase
Quadrature
Complex
Outof-phase
A wire of one kilometre length has a resistance of 20 . If the length is halveda then the new resistance is ___ the original resistance.
Half
Twice
One-fourth
Three times
Which of the following capacitors has the highest cost per F?
Plastic
Air
Mica
Electrolytic
When the net reactance in a series coil-capacitor circuit is zero at frequency fa the nature of its reactance of frequency 2f is
Inductive
Capacitive
Resistive
Infinite
Which factor does not affect resistance?
Length
Resistivity
Cross-sectional area
Mass
When current and voltage arte in phase in an ac circuita the ___ is equal to zero.
Resistance
Reactance
Inductance
Capacitance
A trimmer is a variable capacitor in which capacitance is varied by changing the
Number of plates
Dielectric
Distance between plates
Plate area
For a linear circuita ___ voltage or current is used to calculate average power.
Rms
Peak
Average
Instantaneous
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
When frequency of an ac wave decreasesa the value of XLin a coil
Approaches zero
Gets larger positively
Gets larger negatively
Stays constant
Which of the following capacitors are used only in dc circuits?
Mica
Ceramic
Mylar
Electrolytic
An intermittent and non-symmetrical alternating current like that obtained from the secondary winding of an induction coil
Faradic current
Transient ac current
Inductive current
Capacitive current
Electric energy refers to
Volt divided by coulomb
Voltampere
Volt-coulomb
Watt divided by time
Series resonance occurs when
XL= XC
XL= R
Z = R
Both A and C
It is impossible to change the voltage across a capacitor instantlya as this would produce ___ current.
Infinite
Zero
Low
High
The temperature coefficient of resistance of electrolytes is
Negative
Positive
Zero
Infinite
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
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
A capacitance of 0.05 F equals
0.05 x 106F
0.05 x 10-6F
0.05 x 10-12F
0.05 x 1012F
Which of the following describes the action of a capacitor?
Stores electrical energy
Opposes changes in current flow
Creates a dc resistance
Converts ac to dc
Which of the following has a positive temperature coefficient?
Mica
Manganin
Silicon
Carbon
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 elements is active?
Resistor
Inductor
Capacitor
Ideal voltage source