When two resistors of $R \ \Omega$ value are connected in parallel,what is the equivalent resistance?

$A$ 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 $\text{ A}$)?

$A$ wire of resistance $R$ is bent into an equilateral triangle and an identical wire is bent into a square. The ratio of the equivalent resistance between the two end points of an edge of the triangle to that of the square is

$A$ student has $10$ resistors of resistance $r$. The minimum resistance made by him from given resistors is

Two bulbs,one of $200 \,W$ and the other of $100 \,W$ are connected in series with a $100 \,V$ battery which has no internal resistance. Then,

$A$ conductor of resistance $3 \Omega$ is stretched uniformly until its length is doubled. The wire is now bent in the form of an equilateral triangle. The effective resistance between the ends of any side of the triangle in ohms is