Two electric bulbs ($60\,W$ and $100\,W$ respectively) are connected in series. The current passing through them is

Four $4 \Omega$ resistors are connected together along the edges of a square. $A$ $12 \text{ V}$ battery with an internal resistance of $2 \Omega$ is connected across a pair of the diagonally opposite corners of the square. The power dissipated in the circuit is (in $\text{ W}$)

Write the equation for the equivalent resistance of $n$ resistors connected in series and the equation for the equivalent resistance of $n$ resistors connected in parallel.

Consider two circuits, $(A)$ and $(B)$, each having two resistors. One of them has a positive temperature coefficient of resistance, $+\alpha$, while the other one has a negative temperature coefficient of resistance, $-\alpha$. The current through these circuits are denoted by $I_A$ and $I_B$. At initial temperature, the resistance of the two resistors is $R_0$. As the temperature is increased, the correct option that describes the variation of current in these circuits is:

Three resistances,each of $1\,\Omega$,are joined in parallel. Three such combinations are put in series,then the resultant resistance will be ............. $\Omega$.

By using only two resistance coils—singly,in series,or in parallel—one should be able to obtain resistances of $3$,$4$,$12$,and $16\,\Omega$. The separate resistances of the coils are: