Temperature Dependence of Resistivity

The variation of the resistance of a metallic conductor with temperature is shown in Fig.

State why the resistance of the conductor increases with the rise in temperature.

The variation of the resistance of a metallic conductor with temperature is shown in Fig.

Calculate the temperature coefficient of resistance from the graph.

The voltage-current variation of two metallic wires $X$ and $Y$ at constant temperature are shown in Fig. Assuming that the wires have the same length and the same diameter, explain which of the two wires will have larger resistivity.

$I$-$V$ graph for a metallic wire at two different temperatures, $T_1$ and $T_2$ is as shown in Fig. 3.256. Which of the two temperatures is lower and why?

Choose the correct alternative:

The resistivity of a semiconductor increases/decreases rapidly with increasing temperature.

Choose the correct alternative:

The resistance of graphite and most nonmetals increases/decreases with increase in temperature.

Choose the correct alternative:

Doping a semiconductor (with small traces of impurity atoms) reduces/increases its resistivity.

Answer the following questions:

In which respect, does a nearly discharged lead-acid secondary cell differ mainly from a freshly charged cell in its emf or in its internal resistance?

Answer the following questions:

It is easier to start a car engine on a warm day than on a chilly day. Why?

Answer the following questions:

It is easier to confine electric current to definite paths (by the use of electric insulators) than to direct heat flow along definite routes using heat insulators. Why?

Two materials $\mathrm{Si}$ and $\mathrm{Cu}$ (or $\mathrm{Ga}$ $\mathrm{As}$ and $\mathrm{Ag}$) are cooled from $300 \mathrm{K}$ to $60 \mathrm{K}$. What will be the effect on their resistivity?

Why does the conductivity of a semiconductor increase with rise of temperature?

Letter $A$ as shown in Fig. has resistances on each side of arm. Calculate the total resistance between two ends of the legs.

Find the equivalent resistance between points $A$ and $B$ in Fig.

In the circuit shown in Fig, $R_1=4 \mathrm{\Omega }, R_2=R_3=5 \mathrm{\Omega }, R_4=10 \mathrm{\Omega }$ and $\xi =6 \mathrm{V}$. Work out the equivalent resistance of the circuit and the current in each resistor.

In the circuit diagram shown in Fig. voltmeter reads $30 \mathrm{V}$ when connected across $400 \mathrm{\Omega }$ resistance. Calculate what the same voltammeter reads when it is connected across $300 \mathrm{\Omega }$ resistance.

Find the potential difference between the point $A$ and $B$ for the network shown in Fig.

Find the equivalent resistance of the networks shown in Fig. between the points $A$ and $B$

Calculate the resistance between points $A$ and $B$ for the following networks:

Calculate the equivalent resistance between points $A$ and $B$ in each of the following networks of resistors: