A galvanometer has a sensitivity of $60$ divisions per ampere. When a shunt is used, its sensitivity becomes $10$ divisions per ampere. What is the value of the shunt used if the resistance of the galvanometer is $20 \mathrm{\Omega }$?

A galvanometer has a resistance of $8 \mathrm{\Omega }$. It gives a full-scale deflection for a current of $10 mA$. It is to be converted into an ammeter of range $5 A$. The only shunt resistance available is of $0.02 \mathrm{\Omega }$, which is not suitable for this conversion. Find the value of resistance $R$ that must be connected in series with the galvanometer (Figure) to get ammeter of desired range.

The circuit shown in Figure is used to measure the resistance $R$. The ammeter reads $0.13 A$ and the voltmeter reads $117 V$. The resistance of the ammeter is $0.015 \mathrm{\Omega }$ and that of the voltmeter is $9000 \mathrm{\Omega }$. Find the value of $R$.