Which of the following is the most popular waveform?
Sinusoidal
Square wave
Triangular
Sawtooth
Correct Answer :
A. Sinusoidal
Related Questions
What is the rms value of a square wave?
Equals its peak value
Equals its peak-to-peak value
Peak divided by square root of two
Peak divided by pi
Form its definitiona the unit of electric fielda is the N/C and equivalent unit of is the
V(m)2
V(m)
V/m2
V/m
Which of the following conditions is not true for a series RLCcircuit at resonance?
Z = jXL
XL= XC
The power factor is one
The magnitude of Z is
Points to be considered in choosing a capacitor
Working voltage
Type of dielectric
Capacitance
All of the above
Two complex numbers or phasors are said to be conjugate if they
Differ only in the algebraic sign of their quadratic components
Differ only in the algebraic sign of their real components
Are equal in their real and quadrature components including alge
Are equal in their real components but differ in their quadrature components i ncluding algebraic signs.
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
The presence of an electric current is made known by
Electric shock
Effects produced
Magnetic shock
Flashing
The reciprocal of a complex number is
A complex number
A real number
An imaginary number
A whole number
For parallel capacitorsa total charge is
The sum of individual charges
Equal to the charge of either capacitors
Equal to the product of the charges
The quotient of the charges
The Q-factor of a parallel resonant circuit is also known as
Voltage magnification factor
Current magnification factor
Gain magnification factor
Resonance magnification factor
Series resonance occurs when
XL= XC
XL= R
Z = R
Both A and C
What is the resonant frequency of a circuit when L of 3 microhenrys and C of 40 picofarads are in series?
14.5 kHz
145 MHz
14.5 MHz
145 kHz
In an ac circuit with a resistive branch and an inductive branch in parallela the
Voltage across the inductance leads the voltage across the resistance by 90°
Resistive branch current is 90° out of phase with the inductive branch current
Resistive and inductive branch currents have the same phase
Resistive and inductive branch currents are 180° outof-phase
An impedance given by 90 -45� is a/an ___ impedance.
Inductive
Conductive
Resistive
Capacitive
If a capacitor is rated for 200V dca what is its effective ac working voltage?
50 V
100 V
200 V
400 V
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
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
The farad is not equivalent to which of the following combination of units
CV2
C2/J
C/V
J/V2
If the inductance is decreaseda the impedance of the circuit containing a resistor a capacitor and an inductor connected in series to an ac source
Decreases
Increases
Decreases or increases
Decreasesa increases or remains the same
VL= VCin a series RLCcircuit when
The value of the impedance is minimum
The power factor is zero
The current leads the total voltage by 90�
The total voltage is zero
What increases the resistance of wire at high frequencies?
Temperature
Voltage
Skin effect
Insulation
In adding or subtracting phasor quantitiesa ___ form is the most convenient.
Polar
Rectangular
Trigonometric
Exponential
Which of the following materials has the lowest dielectric strength?
Glass
Paper
Mica
Teflon
The rms value of a triangular or sawtooth waveform is ___ tim value.
Which of the following has negative temperature coefficient?
Carbon
Nickel
Brass
Constantan
Electric energy refers to
Volt divided by coulomb
Voltampere
Volt-coulomb
Watt divided by time
A capacitor is used to
Block dc current
Pass dc current
Open voltage source
Short the voltage source
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 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
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