A 10 V battery of negligible internal resistance is connected across a 200 V battery and a resistance of 38Ω as shown in the figure. Find the value of the current in the circuit.
Draw a graph to show the variation of resistance of a metal wire as a function of its diameter keeping its length and material constant.
Graph showing the variation of current versus voltage for a material GaAs is shown in the figure, identify the region of :
How does one explain increase in resistivity of a metal with increase in temperature ?
How does the random motion of free electrons in a conductor get affected when a potential difference is applied across its ends ?
Show variation of resistivity of copper as a function of temperature in a graph.
The plot of the variation of potential difference across a combination of three identical cells in series, versus current is shown below. What is the emf and internal resistance of each cell ?
When electrons drift in a metal from lower to higher potential, does it mean that all the free electrons of the metal are moving in the same direction ?
Write the expression for the drift velocity of charge carriers in a conductor of length l across which a potential difference V is applied.
The emf of a cell is always greater than its terminal voltage. Why ? Give reason.
An electron is accelerated through a potential difference V. Write the expression for its final speed, if it was initially at rest.
Define temperature coefficient of resistivity.
Define the conductivity of a conductor. Write its SI unit.
Define the term mobility of charge carriers in a conductor. Write its S.I. unit.
Give an example of a material each for which temperature coefficient of resistivity is:
(i) positive, (ii) negative.