What determines the magnitude of electric current?
The rate at which electrons are produced
The type of material used
The current carrying capacity of the circuit
The rate at which electrons pass a given point
Correct Answer :
D. The rate at which electrons pass a given point
Related Questions
A coil of inductance L has an inductive reactance of XLin an ac circuit in which the effective current is I. The coil is made from a superconducting material. The rate at which power is dissipated in the coil is
I2XL
IXL
IXL2
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
Parallel resonant circuit is sometimes called as
Acceptor circuit
Rejector circuit
Inductive circuit
Capacitive circuit
The area of capacitor plates increases two timesa then its capacitance
Increases two times
Increases four times
Decreases two times
Decreases four times
What maximum voltage can be applied across the capacitor of time?
Working voltage
Surge voltage
Stray voltage
Peak voltage
Resistor with colored bands in the body
Wire-wound resistor
Carbon-composition resistor
Potentiometer
Rheostat
Series resonance occurs when
XL= XC
XL= R
Z = R
Both A and C
When two complex conjugates are subtracteda the result is a
Quadrature component only
Complex component
In-phase component
Real component
In a series RLCcircuit
The current lags VLby 90�
The current leads VLby 90�
XL leads Xcby 90�
Z = jXL at resonance
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
What is the form factor of a triangular wave?
A capacitor is used to
Block dc current
Pass dc current
Open voltage source
Short the voltage source
Which of the following capacitors are used only in dc circuits?
Mica
Ceramic
Mylar
Electrolytic
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
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
At what frequency will an inductor of 5mH have the same reactance as a capacitor of 0.1 F?
7.12 kHz
7.12 Hz
7.12MHz
7.12 GHz
Of the equivalent combination of unitsa which one is not equal to watt?
2/V
AV
A2
J/s
For a series ACcircuita ___ is not used as a reference phasor.
Voltage
Impedance
Current
Conductance
The maximum power transfer theorem is used in
Power system
Electronic system
Refrigeration
Air conditioning
The usual load of a dc circuit is a/an
Resistor
Capacitor
Inductor
Both inductor and capacitor
In calculating maximum instantaneous power ___ voltage or current is used.
Peak
Average
Rms
Instantaneous
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
Kirchhoff�s laws (KCL and KVL) are applicable to
DCcircuits
ACcircuits
DC as well as AC circuits
Passive networks alone
Which of the following has negative temperature coefficient?
Carbon
Nickel
Brass
Constantan
Which of the following is a way of decreasing mutual inductance?
Moving the coils closer
Moving the coils apart
Decreasing the number of turns of either coil
Increasing the number of turns of either coil
The result of rust in electrical (wire) connection is
Inductance
Conductance
Impedance
Resistance
The potential gradient in a cable is maximum in
Conductor
Outer sheath
Insulation
Uniformly all over
For greater accuracya the value of phase angle should be determined from
Cos
Tan
Sin
Sec
Which of the following is the most popular waveform?
Sinusoidal
Square wave
Triangular
Sawtooth
The superposition theorem is used when the circuit contains
Reactive elements
Active elements
Number of voltage sources
Single voltage source