Two bulbs $X$ and $Y$ having the same voltage rating and power ratings of $40\, W$ and $60\, W$ respectively are connected in series across a potential difference of $300\, V$. Then:

The current $I_{1}$ (in $A$) flowing through the $1\; \Omega$ resistor in the following circuit is:

$A$ circular coil of total resistance $40 \Omega$ has two points '$P$' and '$Q$' on its circumference. The arc length between '$P$' and '$Q$' is such that the coil is divided into two parts with resistances $30 \Omega$ and $10 \Omega$. These points are connected to a $16 \text{ V}$ battery with an internal resistance of $0.5 \Omega$. What is the value of the current '$I$' flowing through the circuit (in $\text{ A}$)?

In the given circuit, the current in resistance $R_3$ is: (in $\,A$)

You are given $n$ resistors each of resistance $r$. They are first connected to get the minimum possible resistance. In the second case,they are again connected differently to get the maximum possible resistance. Calculate the ratio between minimum and maximum values of resistance so obtained.

$A$ straight uniform wire of resistance $36 \Omega$ is bent in the form of a semi-circular loop. The effective resistance between the ends of the diameter of the semi-circular loop is