When the temperature of copper wire is increased its resistance is
Increased
Decreased
Constant
Zero
Correct Answer :
A. Increased
Related Questions
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
If one resistance in a series connection is opena then
The current is zero in all the other resistances
The current is maximum in all the other resistances
The voltage is zero across the open resistance
The voltage is infinite across the open resistance
The reason why alternating current can induce voltage is
It has high peak value
It has a stronger magnetic field than direct current
It has a constant magnetic field
It has a varying magnetic field
An inductance of 1 mH is
0.001 H
0.01 H
0.0001 H
0.10 H
Parallel resonant circuit is sometimes called as
Acceptor circuit
Rejector circuit
Inductive circuit
Capacitive circuit
What is the most common non-sinusoidal waveform?
Square wave
Triangular wave
Trapezoidal wave
Sawtooth wave
What is the form factor of a triangular wave?
The impedance in the study of electronics is represented by resistan
Inductance
Capacitance
Inductance and capacitance
Reactance
The ratio of the flux density to the electric field intensity in the dielectric is called
Permittivity
Field intensity
Permeability
Elasticity
The farad is not equivalent to which of the following combination of units
CV2
C2/J
C/V
J/V2
If three 9 mH inductors are connected in parallel without mutual inductance then the total i nductance is
3 mH
9 mH
27mH
18 mH
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
What is the hot resistance of a 100 Wa 220 V incandescent lamp?
If an emf in circuit A produces a current in circuit Ba then the same emf in circuit Bproduces the same current in circuit ? this theorem is known as
Maximum power transfer theorem
Millman�s theorem
Reciprocity theorem
Norton�s theorem
Which waveform in which the rms value and the mean value are equal?
Square wave
Triangular wave
Sine wave
Sawtooth
When two unequal values of resistors are connected in parallel across a dc sourcea greater current flows through the
Higher resistance
Lower resistance
Higher wattage resistance
Lower wattage resistance
And ideal current source has an internal conductance of _____ siem
Infinite
One
Zero
One million
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
Which of the following dielectric materials makes the lowest-capacitance capacitor?
Paper
Mica
Air
Electrolyte
The current is ____ times the maximum current at half-power points of a resonance curve.
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
Of the equivalent combination of unitsa which one is not equal to watt?
2/V
AV
A2
J/s
A capacitor is basically constructed of
Two conductors separated by a dielectric
Two dielectric separated by a conductor
Conductors and dielectric
Conductors and semiconductors
The hot resistance of an incandescent lamp is about ___ times its cold resistance.
A series RL circuit has R of 10 and XL of 5 a its impedance in rectangular form is given by
10 +j 5
10 + j 10
10 ± j 5
10 ± j 10
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 distance between the capacitor plates increases two timesa then its capacitance
Increases two times
Increases four times
Decreases two times
Decreases four times
What theorem is generally used in the analysis of vacuum tubes?
Superposition theorem
Millman�s theorem
Thevenin�s theorem
Norton�s theorem
With double the number of turns by the same length and areaa the inductance is
The same
Doubled
Quartered
Quadrupled
A 0.09 microfarad capacitor is charged to 220 volts. How long in milliseconds will it discharged resistor has a resistance of 20a000 ohms?