Embibe Experts Solutions for Chapter: Current Electricity, Exercise 1: KCET (UG) 2020

If the last band on the carbon resistor is absent, then the tolerance is

A wire of resistance $3 \mathrm{\Omega }$ is stretched to twice its original length. The resistance of the new wire will be:

$\mathrm{I} - \mathrm{V}$ graphs for two different electrical appliances $P$ and $Q$ are shown in the diagram. If ${\mathrm{R}}_{\mathrm{P}}$ and $R_{\mathrm{Q}}$ be the resistances of the devices, then

A copper wire of length $1 \mathrm{m}$ and uniform cross-sectional area $5\times {10}^{-7}{ \mathrm{m}}^2$ carries a current of $1 \mathrm{A}.$ Assuming that there are $8\times {10}^{28}$ free electrons per ${\mathrm{m}}^3$ in copper, how long will an electron take to drift from one end of the wire to the other?

The effective resistance between $P$ and $Q$ for the following network is

Two cells of internal resistances $r_1$ and $r_2$ and of the same emf are connected in series, across a resistor of resistance $R$. If the terminal potential difference across the cells of internal resistance $r_1$ is zero, then the value of $R$ is

Consider an electrical conductor connected across a potential difference $V.$ Let $\Delta q$ be a small charge moving through it in time $\Delta t$. If $I$ is the electric current through it,
(i) the kinetic energy of the charge increases by $IV\Delta t$
(ii) the electric potential energy of the charge decreases by $IV\Delta \mathrm{t}$.
(iii) the thermal energy of the conductor increases by $IV\Delta \mathrm{t}$.

Then the correct statements is/are

In the given arrangement of experiment on metre bridge, if $AD$ corresponding to null deflection of the galvanometer is $X$, what would be its value if the radius of the wire $AB$ is doubled?