$A$ bulb gets dimmer for a moment when a geyser,connected across the same source,is switched on. Why?

You are given a resistance wire of length $50 \,cm$ and a battery of negligible resistance. In which of the following cases is the largest amount of heat generated?

$(a)$ Explain why a conductor offers resistance to the flow of current.
$(b)$ Differentiate between conductor,resistor,and resistance.

$(a)$ How is the direction of electric current related to the direction of flow of electrons in a wire?
$(b)$ Calculate the current in a circuit,if $500 \, C$ of charge passes through it in $10$ minutes.

The amount of charge passing through a cell in $4 \, s$ is $12 \, C$. Find the current supplied by the cell. (in $, A$)

Find out the following in the electric circuit given in the figure:
$(a)$ Effective resistance of two $8\,\Omega$ resistors in the combination.
$(b)$ Current flowing through the $4\,\Omega$ resistor.
$(c)$ Potential difference across the $4\,\Omega$ resistor.
$(d)$ Power dissipated in the $4\,\Omega$ resistor.
$(e)$ Difference in ammeter readings,if any.