The value of temperature coefficient ( ) is dependent upon
The nature of material and temperature
The length of material
The cross-sectional area of the material
The volume of the material
Correct Answer :
A. The nature of material and temperature
Related Questions
A lead conductor has a resistance of 25 at 0 �C. Determine its resistance at -30 �C
What is the most convenient way of achieving large capacitance?
By using multiplate construction
By using air as dielectric
By decreasing distance between plates
By using dielectric of low permittivity
The current is ____ times the maximum current at half-power points of a resonance curve.
The usual load of a dc circuit is a/an
Resistor
Capacitor
Inductor
Both inductor and capacitor
If a capacitor is rated for 200V dca what is its effective ac working voltage?
50 V
100 V
200 V
400 V
Which of the following is a common material used in wire-wound resistors?
Manganin
Carbon
Bronze
German silver wire
What is considered as the most important value of a sine wave?
Effective value
Peak value
Average value
Instantaneous value
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
An impedance given by 90 -45� is a/an ___ impedance.
Inductive
Conductive
Resistive
Capacitive
If three 100-pF capacitors are connected in seriesa then the total capacitance is
300 pF
100 pF
50 pF
33.3 pF
An inductive load always has a ___ power factor
Leading
Lagging
Zero
Unity
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
What is the other name of relative permittivity?
Dielectric strength
Potential gradient
Breakdown voltage
Specific inductance capacity
What refers to such work at very low temperaturesa near absolute zero?
Cryogenics
Superconductivity
Subsonic
Thermionic
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
What maximum voltage can be applied across the capacitor of time?
Working voltage
Surge voltage
Stray voltage
Peak voltage
Which of the following is the peakiest?
Square wave
Sinusoidal wave
Triangular wave
Rectangular wave
If two resistances of 9 and 6 are connected in parallela the total resistance is
What is the total resistance of a two equal valued resistors in series?
The difference of both
The product of both
Twice as one
The sum of their reciprocals
The power factor of a circuit is equal to
RZ
XC/Z
XL/Z
R/Z
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
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
A series-parallel combination of identical resistors will
Increase the power rating compared with one resistor alone
Increase the voltage rating compared with one resistor alone
Reduce the voltage rating compared with resistor alone
Result in an expensive circuit
A term used to express the amount of electrical energy stored in electrostatic field.
Joules
Coulombs
Watts
Electron-volt
In calculating maximum instantaneous power ___ voltage or current is used.
Peak
Average
Rms
Instantaneous
The result of rust in electrical (wire) connection is
Inductance
Conductance
Impedance
Resistance
The factor 0.707for converting peak to rms applies only to
Square waves
Triangle waves
Sawtooth waves
Sine waves
If a coil has a Q of 10a it means that
The energy stored in the magnetic field of the coil is 10 times the energy wasted in its resistance
The energy wasted in its resistance is 10 times the energy stored in the magnetic field of the coil
It is a low Q coil
It is a high Q coil
Series resonance occurs when
XL= XC
XL= R
Z = R
Both A and C
A 0.09 microfarad capacitor is charged to 220 volts. How long in milliseconds will it discharged resistor has a resistance of 20a000 ohms?