$AB$ is a wire of uniform resistance. The galvanometer $G$ shows no current when the length $AC = 20\,cm$ and $CB = 80\, cm$. The resistance $R$ is equal to ………….. $\Omega $

ln a balanced wheat stone bridge, current in the galvanometer is zero. It remains zero when:

$[1]$ battery emf is increased

$[2]$ all resistances are increased by $10\,ohms$

$[3]$ all resistances are made five times

$[4]$ the battery and the galvanometer are interchanged

Explain construction of meter bridge used in laboratory.

In the shown arrangement of the experiment of the meter bridge if $AC$ corresponding to null deflection of galvanometer is $x$, what would be its value if the radius of the wire $AB$ is doubled

In the given figure of meter bridge experiment, the balancing length $AC$ corresponding to null deflection of the galvanometer is $40\,cm$. The balancing length, if the radius of the wire $AB$ is doubled, will be $….cm$