You are given three equal resistors. The number of resistances which can be obtained by joining them in series and in parallel grouping is

Of which physical quantity is the $joule/coulomb$ a unit?

A nichrome wire has a resistance of $10\, \Omega$. Find the resistance of another nichrome wire, whose length is three times and area of cross-section four times the first wire.

Draw a labelled circuit diagram showing three resistors $R_{1}, R_{2}$ and $R_{3}$ connected in series with $a$ battery $(E),$ a rheostat $(R h),$ $a$ plug key $(K)$ and an ammeter $(A)$ using standard circuit symbols. Use this circuit to show that the same current flows through every part of the circuit. List two precautions you would observe while performing the experiment.

What is meant by "electrical resistance" of a conductor ? State how resistance of a conductor is affected when $(i)$ a low current passes through it for a short duration; $(ii)$ heavy current passes through it for about $30$ seconds.

An electric iron draws a current of $0.5\, A$ when the voltage is $200$ volt. Calculate the amount of electric charge flowing through it in one hour.