The hot resistance of an incandescent lamp is about ___ times its cold resistance.
Correct Answer :
A.
Related Questions
Which of the following is a common material used in wire-wound resistors?
Manganin
Carbon
Bronze
German silver wire
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
The second strip of an electronic resistor color-code represents
The multiplier
The second digit of the value
The temperature
The tolerance
What theorem is usually used in the analysis of transistor circuit?
Superposition theorem
Millman�s theorem
Thevenin�s theorem
Norton�s theorem
Which factor does not affect resistance?
Length
Resistivity
Cross-sectional area
Mass
Permeability is otherwise known as
Magnetic conductivity
Magnetic susceptibility
Electric conductivity
Electric susceptibility
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
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
For multi-plate capacitora capacitance is proportional to
Number of plates less one(n ± 1)
Number of plates plus one(n + 1)
Number of plates less two(n - 2)
Number of plates (n)
What is the reading of an ohmmeter for a shorted capacitor?
Zero
Infinity
k
M
When current and voltage arte in phase in an ac circuita the ___ is equal to zero.
Resistance
Reactance
Inductance
Capacitance
What rating of a resistor determines its ability to absorb heat?
Wattage
Ohmic
Current
Voltage
A factor that states how much the resistance changes for a change in temperature?
Resistivity
Specific resistance
Coefficient of temperature change
Temperature coefficient of resistance
The Q-factor of a parallel resonant circuit is also known as
Current magnification factor
Voltage magnification factor
Load factor
Leakage factor
In liquids and gasesa ionization current results from a flow of
Positive or negative ions
Free electrons
Ions that are lighter in weight than electrons
Protons
Which of the following capacitors are used only in dc circuits?
Mica
Ceramic
Mylar
Electrolytic
A gang capacitor is a variable capacitor in which capacitance is varied by changing the
Dielectric
Number of plates
Plate area
Distance between plates
A tank circuit is a
Parallel LC circuit
Series LCcircuit
A resonant circuit
A non-resonant circuit
What is the complex impedance of a circuit with an absolute resistance of 300 ?
0 + j 300
300 + j 90
0 ± j 300
300 +j 0
What theorem is generally used in the analysis of vacuum tubes?
Superposition theorem
Millman�s theorem
Thevenin�s theorem
Norton�s theorem
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
Another term for superconductor.
Generic conductor
Ultraconductor
Cryotron
Cryogenic conductor
It is impossible to change the voltage across a capacitor instantlya as this would produce ___ current.
Infinite
Zero
Low
High
Which of the following is the statement of Ohm�s law?
Electric current is directly proportional to both voltage and resistance
Electric current varies directly as the voltage and inversely as the resistance
Electrical power is directly proportional to the resistance and inversely as the current squared
Electrical power is directly proportional to both voltage squared and the resistance
An impedance given by 90 -45� is a/an ___ impedance.
Inductive
Conductive
Resistive
Capacitive
The ohmic value of a resistor with negative temperature coefficient
Increases with increasing temperature
Increase with decreasing temperature
Stays unchanged with temperature change
Stays unaffected even with increasing temperature
For greater accuracya the value of phase angle should be determined from
Cos
Tan
Sin
Sec
What can be used to estimate resonant frequency and to find reactance at any frequency for any value of capacitor or inductor?
Smith chart
Reactance chart
Impedance chart
Resonance chart
What is the specific resistance of a pure silicon?
55 -mm
55 -m
55 -cm
55 k -m
In adding or subtracting phasor quantitiesa ___ form is the most convenient.
Polar
Rectangular
Trigonometric
Exponential