Voltmeter MCQ - Practice Questions with Answers

A galvanometer of resistance $100\mathrm{\Omega }$ has 50 divisions on its scale and has sensitivity of $20\mu A/$ division. It is to be converted to a voltmeter with three ranges, of $0-2\mathrm{V},0-10\mathrm{V}$ and $0-20\mathrm{V}$. The appropriate circuit to do so is :

A voltmeter having a resistance of $1800\mathrm{\Omega }$ is employed to measure the potential difference across $200\mathrm{\Omega }$ resistance which is connected to dc power supply of 50 V and internal resistance $20\mathrm{\Omega }$. What is the approximate percent change in the P.D across $200\mathrm{\Omega }$ resistance as a result of connecting the voltmeter across it?

A galvanometer has a resistance of $30\mathrm{\Omega }$, and a current of 2 mA is needed for a full scale deflection. The resistance (in $\mathrm{\Omega }$ ) that should be used to convert it into a voltmeter in the 0.2 V range is

A 100V voltmeter has an internal resistance of 20k$\mathrm{\Omega }$.. is connected in series with a large resistance R across a 110V line. If the voltmeter reads 5V then the magnitude of R (in $k\mathrm{\Omega }$ ) is

 A galvanometer , whose resistance is 50 ohm , has 25 divisions in it. When a current of 4 X 10^-4 A passes through it , its needle (pointer) deflects by one division. To use this galvanometer as a voltmeter of range 2.5 V , it should be connected to a resistance (in ohm)  of : 

The actual value of resistance $R$, shown in the figure is $30\mathrm{\Omega }$. This is measured in an experiment as shown using the standard formula $R=\frac{V}{I}$, Where } V and } I are the readings of the voltmeter and ammeter, respectively. If the measured value of R is $5\mathrm{\%}$ less, then the internal resistance (in $\mathrm{\Omega }$ ) of the voltmeter is: (Round the answer to the nearest integer)

An ideal voltmeter V is connected to a $20\mathrm{\Omega }$ resistor and a battery with emf 10V and internal resistance $0.5\mathrm{\Omega }$ as in the figure.

The ratio of current in $20\mathrm{\Omega }$ resistor with the voltage of the battery

In the given circuit, the voltmeter and the electric cell are ideal. Find the reading of the voltmeter

A constant 60 V d.c. supply is connected across two resistors of resistance $400\mathrm{k}\mathrm{\Omega }$ and $200\mathrm{k}\mathrm{\Omega }$. What is the reading of the voltmeter, also of resistance $200\mathrm{k}\mathrm{\Omega }$, when connected across the second resistor as shown in Figure?

An ammeter A of finite resistance and a resistor R are joined in series to an ideal cell C. A Potentiometer P is joined in parallel to R. The ammeter reading is ${\mathrm{I}}_0$ and the potentiometer reading is ${\mathrm{V}}_0$. P is now replaced by a voltmeter of finite resistance. The ammeter reading now is I and the voltmeter reading is V. Then