In a meter bridge experiment, a resistance of $9 \Omega$ is connected in the left gap and an unknown resistance greater than $9 \Omega$ is connected in right gap. If the resistance in the gaps are interchanged, the balancing point shifts by 10 cm . The unknown resistance is

Current sensitivities of two galvanometers $G_1$ and $G_2$ of resistances $100 \Omega$ and $50 \Omega$ are $10^8 \mathrm{div} / \mathrm{A}$ and $0.5 \times 10^5 \mathrm{div} / \mathrm{A}$ respectively. The galvanometer in which the voltage sensitivity is more is $100 \Omega$

A battery of emf 8 V and internal resistance $0.5 \Omega$ is being charged by a 120 V DC supply using a series resister of $15.5 \Omega$. The terminal voltage of 8 V batter) during charging is

Resistance of a wire is $8 \Omega$. It is drawn in such a way that it experiences a longitudinal strain of $400 \%$. The final resistance of the wire is