Copper and Silicon are cooled from 300 K to 60 K . The specific resistance

decreases in copper but increases in silicon

increases in copper but decreases in silicon

A silver wire has a resistance of 2 . 7 Ω at 100 ° C . Determine the temperature coefficient of resistivity of silver.

The temperature coefficient of silver is 0 . 0039 ∘ C - 1 . The temperature coefficient of resistance for a resistor is determined by measuring the resistances values over an appropriate temperature range. The TCR is calculated as the average slope of the resistance value over this interval. This is accurate for linear relations, since the TCR is constant at every temperature.The resistance-change factor per degree Celsius of temperature change is called the temperature coefficient of resistance. This factor is represented by the Greek lower-case letter “alpha”. A positive coefficient for a material means that its resistance increases with an increase in temperature.

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How does resistivity of nichrome vary with temperature?

Important Questions on Current Electricity

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The resistance of the platinum wire of a platinum resistance thermometer at the ice point is

5 Ω

and at steam point is

5.23 Ω

. When the thermometer is inserted in a hot bath, the resistance of the platinum wire will be

5.795 Ω

. Calculate the temperature of the bath.

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

$I$ and $V$ are respectively the current and voltage in a metal wire of resistance $R .$ The $I - V$ graph for the two different temperatures $T_{1}$ and $T_{2}$ are given, then

Question Image

HARD

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The resistance of a conductor at

15 ° C

16 Ω

and at

100 ° C

20 Ω .

What will be the temperature coefficient of resistance of the conductor?

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The temperature

(T)

dependence of resistivity

(ρ)

of a semiconductor is represented by

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

Which of the following graph represents the variation of resistivity

(ρ)

with temperature

(T)

for copper?

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

What will be the resistance of a wire at 0 degree celsius, if its resistance is

5 ohm

50

degree celsius and

6 ohm

100

degree celsius?

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

When the temperature of a conductor increases, the ratio of conductivity and resistivity _____

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

Alloys are used to make the standard resistance. Why?

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The solids which have the negative temperature coefficient of resistance are:

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The resistance of a wire at

20 ° C

20 Ω

and

500 ° C

60 Ω

. At which temperature, its resistance will be

25 Ω ?

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

Constantan wire is used in making standard resistances because its

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The conductivity of semiconductor increases with increase in temperature because

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

Copper and Silicon are cooled from

300 K

60 K

. The specific resistance

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

A heating element has a resistance of

100 Ω

at room temperature. When it is connected to a supply of

220 V

, a steady current of

2 A

passes in it and temperature is

500^{o} C

more than the room temperature. The temperature coefficient of resistance of the heating element is

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

Which of the following quantities does not change when a resistor is heated by passing current through it?

EASY

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

A silver wire has a resistance of

2.7 Ω

100 ° C

. Determine the temperature coefficient of resistivity of silver.

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The Resistance of a conductor is

XΩ

0^{o} C

temperature. Find the temperature at which the resistance of conductor becomes

3 XΩ

. The temperature coefficient of resistance for conductor is

0.4 \times 10^{- 2} {}^{o}C^{- 1}

which is constant.

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

The temperature co-efficient of resistance of a wire is

0.00125 / ° C .

Its resistance is

1 Ω

300 K .

At what temperature, its resistance will be

2 Ω

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

In a platinum resistance thermometer, the resistances of the wire at ice point and steam point are of

4 Ω

and

4.25 Ω

respectively. When the thermometer is kept in a hot water bath, whose temperature is not known, the resistance of the wire is found to be

4.5 Ω .

The temperature of the hot water bath is

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Factors Affecting Resistance

In an experiment, the resistance of a material is plotted as a function of temperature (in some range). As shown in the figure, it is a straight line.

Question Image

One may conclude that

How does resistivity of nichrome vary with temperature?

Important Questions on Current Electricity

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