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

The equivalent capacitance across $A \& B$ is

The time constant of the shown circuit for charging is

Consider the circuit below, with an initially uncharged capacitor and two identical resistors. At the instant the switch is closed :

Consider the $MB$ shown in the diagram, let the resistance $X$ have temperature coefficient ${\alpha }_1$ and the resistance from the $RB$ have the temperature coefficient ${\alpha }_2.$ Let the reading of the meter scale be $10 \mathrm{cm}$ from the $\mathrm{LHS}$. If the temperature of the two resistance increase by small temperature $\mathrm{\Delta }$$T$ then what is the shift in the position of the null point? Neglect all the other changes in the bridge due to temperature rise.

Identify which of the following diagrams represent the internal construction of the coils wound in a resistance box or box ?

A short circuit occurs in a telephone cable having a resistance of $0.45 \mathrm{\Omega } {\mathrm{m}}^{-1}$. The circuit is tested with a Wheatstone bridge. The two resistors in the ratio arms of the Wheatstone bridge network have values of $100 \mathrm{\Omega }$ and $1110 \mathrm{\Omega }$ respectively. A balance condition is found when the variable resistor has a value of $400 \mathrm{\Omega }$. Calculate the distance down the cable, where the short has occurred.

Two wires each of radius of cross section $r$ but of different materials are connected together end to end (in series). If the densities of charge carriers in the two wires are in the ratio $1: 4,$ the drift velocity of electrons in the two wires will be in the ratio :

A current $I$ flows through a uniform wire of diameter $d$when the mean electron drift velocity is $V$ The same current will flow through a wire of diameter $\frac{d}{2}$ made of the same material if the mean drift velocity of the electron is