Embibe Experts Solutions for Chapter: Current Electricity, Exercise 1: West Bengal Board-2018

Name a machine that converts electrical energy into mechanical energy.

Apart from the live wire, what are the two other wires in the household circuit?

Mention one similarity and one dissimilarity between electromotive force and potential difference. 

Two metallic conductors A and B of same lengths have resistivities of $1.6\times {10}^{-8} \mathrm{\Omega m}$ and $3.2\times {10}^{-8} \mathrm{\Omega m}$ respectively. These two conductors are separately connected to the same potential difference. What should be the ratio of their cross-sections in order to have the same current flowing through each of them?

The series combination of two $10 \mathrm{ohm}$ resistances is connected in parallel combination with a $20 \mathrm{ohm}$ resistance. Determine the equivalent resistance of the final combination.

What is meant by electrical power? The rating of a bulb is written as $220 \mathrm{V}-100 \mathrm{W}$. What is its meaning?

Two resistances are to be connected in which combination so that the equivalent resistance becomes less than the individual resistances?

Write down the difference between a semiconductor and a superconductor on the basis of relationship between resistivity and temperature.