Which of the following is a disadvantage of a wire-wound resistor?
It has reactance in radio-frequency circuits
It cannot handle much power
It draws a large amount of current
It cannot handle high voltage
Correct Answer :
A. It has reactance in radio-frequency circuits
Related Questions
The ___ of an alternating quantity is defined as the fractional part of a period or cycle through which the quantity has advanced from selected origin.
Phase
Frequency
Amplitude
Waveform
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
A capacitor opposes change in
Voltage
Current
Voltage and current
Neither voltage nor current
For a triangular and sawtooth waveform the rms voltage or current equals
0.707times peak value
0.577 times peak value
0.577times average value
0.707times rms value
Kirchhoff�s laws (KCL and KVL) are applicable to
DCcircuits
ACcircuits
DC as well as AC circuits
Passive networks alone
The potential gradient in a cable is maximum in
Conductor
Outer sheath
Insulation
Uniformly all over
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
The superposition theorem is used when the circuit contains
Reactive elements
Active elements
Number of voltage sources
Single voltage source
The charging of a capacitor through a resistance follows what law?
Linear law
Hyperbolic law
Inverse-square law
Exponential law
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
The distance between the capacitor plates increases two timesa then its capacitance
Increases two times
Increases four times
Decreases two times
Decreases four times
The impedance in the study of electronics is represented by resistan
Inductance
Capacitance
Inductance and capacitance
Reactance
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
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
Points to be considered in choosing a capacitor
Working voltage
Type of dielectric
Capacitance
All of the above
In a complex resistance-reactance planea XLis represented
By an axis opposite the R axis
By an axis perpendicular to the XC axis
By an axis opposite the XCaxis
By an axis parallel to the R axis
How many coulombs are delivered by a storage battery in 25 hours if it is supplying current at the rate of 3 A?
2.592 x 105C
2.592 x 103 C
2.592 x 108 C
2.592 x 1012 C
With double the number of turns by the same length and areaa the inductance is
The same
Doubled
Quartered
Quadrupled
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
A capacitor is used to
Block dc current
Pass dc current
Open voltage source
Short the voltage source
The reason why electrical appliances are not connected in series.
Greater electrical power saving
Power loss is minimum
Appliances have different current ratings
All of the above
In a complex number 5 + j 10a 10 is called ___ part.
Imaginary
Real
Conjugate
Integer
The current is ____ times the maximum current at half-power points of a resonance curve.
A lead conductor has a resistance of 25 at 0 �C. Determine its resistance at -30 �C
A trigger circuit consisting of a capacitor of 0.01 F is connected in series with a resistor. If the circuit requires 100 Vdcto operatea determine the value of the resistor when time constant is 0.009s.
900 k
900 M
900 G
The unit of elastance is
Farad
Daraf
Siemen
Henry
The charging of a capacitor through a resistance obeys
Exponential law
Logarithmic law
Linear law
Square law
Under the conditions of maximum power transfera a voltage source is delivering a power of 15 W to the load. What is the power generated by the source?
60 W
30 W
15 W
4 W
When two in-phase sine waves that have identical frequency and amplitude are added togethera then the result is a sine wave with ___ the amplitude of either.
Half
Twice
Four times
One-fourth
Which one of the following elements serves as a protection against overload?
Fuse
Switch
Resistor
Relay