The equivalent resistance of the circuit shown in the figure is ............. $\Omega$

When a wire of uniform cross-section $a$,length $ℓ$,and resistance $R$ is bent into a complete circle,the resistance between any two diametrically opposite points will be .......

Some bulbs are connected in series to a $220\, V$ supply. If one bulb gets fused and the remaining bulbs are reconnected in series to the same supply,the brightness in the room will:

What equal length of an iron wire and a copper-nickel alloy wire, each of $2 \; mm$ diameter, connected in parallel, gives an equivalent resistance of $3 \; \Omega$? (Given: resistivities of iron and copper-nickel alloy wire are $12 \; \mu\Omega \cdot cm$ and $51 \; \mu\Omega \cdot cm$ respectively) (in $m$)

The equivalent resistance of three unequal resistors connected in parallel is $1 \ \Omega$. If the ratio of two of them is $1:2$ and all resistance values are integers,what is the value of the largest resistor in ohms?

If the ratio of the equivalent resistance of two resistors $R_1$ and $R_2$ in series to that in parallel is $n$,then: