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.