Embibe Experts Solutions for Chapter: Current Electricity, Exercise 1: Punjab Board-2019

For alloys the value of temperature coefficient of resistance is very high.

A wire with an area of cross section $10 {\mathrm{mm}}^2$ has resistance $5\Omega$,when a potential difference across its ends is $25 \mathrm{V}$.calculate the drift velocity of the electron. Given the number density of electrons is $5\times {10}^{20} \mathrm{electron}/{\mathrm{m}}^3$.

Define e..m.f. of a cell. How can you compare the emf of two cells using potentiometer ?

For metal conductors the electrical resistivity deceases with the rise in temperature

Given three resistors of resistances $1 \Omega , 2\Omega and 3\Omega$. How will you combine them to get an equivalent resistance of $\frac{11}{5}\Omega$..

State Wheatstone bridge principle. Use Kirchhoff's Laws to obtain the relation between the resistance in four arms of the Wheatstone bridge by drawing circuit diagram.

A common emitter (CE) transistor has a current gain of $100$. If emitter current is $8.08 \mathrm{mA}$ma, find the base and collector current.

Explain the principle, construction and working of a cyclotron with the help of a labelled diagram. State its two limitations.