Rajesh Singh, Indu Gupta and, Sikha Sharma Solutions for Chapter: Electricity, Exercise 1: Multiple Choice Questions (MCQs)

A student carries out an experiment and plots the $\mathrm{V}-\mathrm{I}$ graph of three samples of nichrome wire with resistances ${\mathrm{R}}_1 , {\mathrm{R}}_2$ and ${\mathrm{R}}_3$ respectively as shown in figure. Which of the following is true?

If the current $\mathrm{I}$ through a resistor is increased by $100\%$ (assume that temperature remains unchanged), what will be the increase in power dissipated?

The resistivity does not change if

In an electrical circuit three incandescent bulbs. $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ of rating  $40 \mathrm{W} , 60 \mathrm{W}$ and $100 \mathrm{W}$, respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?

In an electrical circuit, two resistors of $2 \mathrm{\Omega }$ and $4 \mathrm{\Omega }$ respectively are connected in series to a $6 \mathrm{V}$ battery. The heat dissipated by the $4 \mathrm{\Omega }$ resistor in $5 \mathrm{s}$ will be 

An electric kettle consumes $1 \mathrm{k} \mathrm{W}$ of electric power when operated at $220 \mathrm{V}$. A fuse wire of what rating must be used for it?

Two resistors of resistance $2 \mathrm{\Omega }$ and $4 \mathrm{\Omega }$ when connected to a battery will have

Unit of electric power may also be expressed as