The $I-V$ graph for a conductor at two different temperatures $100^{\circ} \mathrm{C}$ and $400^{\circ} \mathrm{C}$ is as shown in the figure. The temperature coefficient of resistance of the conductor is about (in per degree Celsius)
An electric blub of $60 \mathrm{~W}, 120 \mathrm{~V}$ is to be connected to 220 V source. What resistance should be connected in series with the bulb, so that the bulb glows properly?
In an experiment to determine the temperature coefficient of resistance of a conductor, a coil of wire $X$ is immersed in a liquid. It is heated by an external agent. A meter bridge set up is used to determine resistance of the coil $X$ at different temperatures. The balancing points measured at temperatures $t_1=0^{\circ} \mathrm{C}$ and $t_2=100^{\circ} \mathrm{C}$ are 50 cm and 60 cm respectively. If the standard resistance taken out is $S=4 \Omega$ in both trials, the temperature coefficient of the coil is
A moving electron produces