Chapter 34

A moving coil galvanometer has 150 equal divisions, Its current sensitivity is 10 divisions per milli-ampere and voltage sensitivity is 2 divisions per milli-volt. In order that each divisions reads $1\mathrm{V}$, What will be the resistance in ohms needed to be connected in series with the coil? (A) ${10}^3$ (B) 99995 (C) 9995 (D) ${10}^5$

A galvanometer of resistance $200\mathrm{\Omega }$ gives full scale deflection for a current of ${10}^{-3}\mathrm{A}$. To convert it into an ammeter capable of measuring upto $1\mathrm{A}$. What resistance should be connected in parallel with it ? (A) $2\times {10}^{-1}\mathrm{\Omega }$ (B) $2\mathrm{\Omega }$ (C) $2\times {10}^{-3}\mathrm{\Omega }$ (D) $2\times {10}^{-6}\mathrm{\Omega }$

A galvanometer with resistance $100\mathrm{\Omega }$ is converted into an ammeter with a resistance of $0.1$. The galvanometer shows full scale deflection with current of $100\mu \mathrm{A}$. Then what will be the minimum current in the circuit for full scale deflection of galvanometer ? (A) $0.1001\mathrm{mA}$ (B) $100.1\mathrm{mA}$ (C) $1000.1\mathrm{mA}$ (D) $1.001\mathrm{mA}$

The range of a galvanometer of resistance $\mathrm{G}$ ohm is $\mathrm{V}$ volt. The resistance required to be connected in series with it in order to convert it into voltmeter of range $\mathrm{nV}$ volt will be (A) (G/n) (B) $\mathrm{nG}$ (C) $(\mathrm{n}-1)\mathrm{G}$ (D) $[\mathrm{G}/(\mathrm{n}-1)]$

The seave of a galvanometer of resistance $100\mathrm{Q}$ contains 25 divisions. It gives a deflection of 1 division on passing a current of $4\times {10}^{-4}\mathrm{A}$. The resistance in ohm to be added to it. so that it may become a voltmeter of range $2.5\mathrm{V}$ is (A) 250 (B) 300 (C) 150 (D) 100

A galvanometer of resistance $200\mathrm{\Omega }$ gives full scale deflection with 15 milli-ampere current. In order to convert it into a $15\mathrm{V}$ range voltmeter. What is the value of resistance connected in series ? (A) $1000\mathrm{\Omega }$ (B) $800\mathrm{\Omega }$ (C) $2500\mathrm{\Omega }$ (D) $1500\mathrm{\Omega }$

A galvanometer, having a resistance of $50\mathrm{\Omega }$, gives a full scale deflection for a current of $0.05\mathrm{A}$. The length in meter of a resistance wire of area of cross-section $2.97\times {10}^2{\mathrm{cm}}^2$ that can be used to convert the galvanometer into an ammeter which can read a maximum of $5\mathrm{A}$ current is (specific resistance of wire $=5\times {10}^{-7}\mathrm{\Omega }\mathrm{m}$ ) (A) $1.5$ (B) 6 (C) 8 (D) 3

An ammeter of range $5\mathrm{A}$ is to be converted into an voltmer of range $10\mathrm{V}$. If the resistance of ammeter be $0.1$, then what resistance should be connected in series with it ? (A) $4.9\mathrm{\Omega }$ (B) $2.1\mathrm{\Omega }$ (C) $1.1\mathrm{\Omega }$ (D) $1.9\mathrm{\Omega }$

What is the relation between figure of merit $(\mathrm{k})$ and current sensitivity $\left({\mathrm{S}}_1\right)?$ (A) ${\mathrm{S}}_1={\mathrm{k}}^{-1}$ (B) ${\mathrm{S}}_1=(\mathrm{k}/2)$ (C) ${\mathrm{S}}_1=\mathrm{kV}$ (D) ${\mathrm{S}}_1=(\mathrm{k})\mathrm{I}$

One micro-ammeter has a resistance of $100\mathrm{\Omega }$ and a full scale range of $50\mu \mathrm{A}$. ft can be used as a voltmeter or as a higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combinations (s). (A) $5\mathrm{mA}$ range with $1\mathrm{\Omega }$ resistance in parallel (B) $10\mathrm{mA}$ range with $1\mathrm{\Omega }$ resistance in parallel (C) $10\mathrm{V}$ range with $200\mathrm{k}\mathrm{\Omega }$ resistance in series (D) $50\mathrm{V}$ range with $10\mathrm{k}\mathrm{\Omega }$ resistance in series