Give the uses of a galvanometer.

Explain the equation of a shunt.

$A$ moving coil galvanometer has a resistance of $50\,\Omega$ and it indicates full-scale deflection at a current of $4\,mA$. $A$ voltmeter is constructed using this galvanometer and a $5\,k\Omega$ series resistance. The maximum voltage that can be measured using this voltmeter will be close to ......$V$.

If $n$ represents the actual number of deflections in a converted galvanometer of resistance $G$ and shunt resistance $S$,then the total current $I$ when its figure of merit is $K$ will be:

Two identical moving coil galvanometers have $10 \Omega$ resistance and full scale deflection at $2 \mu A$ current. One of them is converted into a voltmeter of $100 \text{ mV}$ full scale reading and the other into an ammeter of $1 \text{ mA}$ full scale current using appropriate resistors. These are then used to measure the voltage and current in the Ohm's law experiment with $R = 1000 \Omega$ resistor by using an ideal cell. Which of the following statement$(s)$ is/are correct?
$(1)$ The measured value of $R$ will be $980.2 \Omega$.
$(2)$ The resistance of the voltmeter will be $50 \text{ k} \Omega$.
$(3)$ The resistance of the ammeter will be $0.02 \Omega$ (rounded off to the $2^{\text{nd}}$ decimal place).
$(4)$ If the ideal cell is replaced by a cell having internal resistance of $5 \Omega$,then the measured value of $R$ will be more than $1000 \Omega$.

$A$ galvanometer with $30$ divisions has a current sensitivity of $20 \, \mu A/division$. Its resistance is $25 \, \Omega$. How will you convert it into an ammeter to measure $1 \, A$ current?