An ammeter of resistance $R$ gives a full-scale deflection when a current of $2 \ A$ passes through it. If it is to be converted into an ammeter to measure a maximum current of $10 \ A$,the required shunt is:

The pointer of a dead-beat galvanometer gives a steady deflection because

The current sensitivity of a moving coil galvanometer is increased by $25 \%$. This increase is achieved only by changing the number of turns of the coils and the area of the cross-section of the wire while keeping the resistance of the galvanometer coil constant. The percentage change in the voltage sensitivity will be $...........\%$

When a galvanometer is shunted with a $4\,\Omega$ resistance,the deflection is reduced to one-fifth. If the galvanometer is further shunted with a $2\,\Omega$ wire,the further reduction in the deflection will be (the main current remains same).

$A$ galvanometer of resistance $100 \Omega$ when connected in series with $400 \Omega$ measures a voltage of up to $10 \ V$. The value of resistance required to convert the galvanometer into an ammeter to read up to $10 \ A$ is $x \times 10^{-2} \Omega$. The value of $x$ is:

$A$ galvanometer of resistance $50 \Omega$ is connected to a battery of $3 \text{ V}$ along with a resistance of $2950 \Omega$ in series,showing a full-scale deflection of $30$ divisions. The additional series resistance required to reduce the deflection to $20$ divisions is: (in $\Omega$)