Figure shows a part of an electric circuit. The potentials at points $$a, b$$ and $$c$$ are $$30 \mathrm{~V}, 12 \mathrm{~V}$$ and $$2 \mathrm{~V}$$ respectively. The current through the $$20 ~\Omega$$ resistor will be,

A student is provided with a variable voltage source $$\mathrm{V}$$, a test resistor $$R_{T}=10 ~\Omega$$, two identical galvanometers $$G_{1}$$ and $$G_{2}$$ and two additional resistors, $$R_{1}=10 ~M \Omega$$ and $$R_{2}=0.001 ~\Omega$$. For conducting an experiment to verify ohm's law, the most suitable circuit is:

Given below are two statements : One is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$.

Assertion A : For measuring the potential difference across a resistance of $$600 \Omega$$, the voltmeter with resistance $$1000 \Omega$$ will be preferred over voltmeter with resistance $$4000 \Omega$$.

Reason R : Voltmeter with higher resistance will draw smaller current than voltmeter with lower resistance.

In the light of the above statements, choose the most appropriate answer from the options given below.

Equivalent resistance between the adjacent corners of a regular n-sided polygon of uniform wire of resistance R would be :