By error, a student places moving-coil voltmeter $V$ (nearly ideal) in series with the resistance in a circuit in order to read the current, as shown. The voltmeter reading will be ............ $V$
Medium
Download our app for free and get started
So if connected in series, a very small current will flow or no current will flow. An ideal voltmeter draws $0$ current from the circuit. So when we arrange it in series, It doesn't work as a voltmeter but as resistance and also the reading is shown by the voltmeter is the voltage across its terminals.
The voltmeter reading will be $12 V$.
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1If $n, e, \tau$ and $m$ are representing electron density, charge, relaxation time and mass of an electron respectively, then the resistance of a wire of length / and cross-sectional area $A$ is given byView Solution
- 2The emf of a battery is $2\, V$ and its internal resistance is $0.5 \,\Omega$. The maximum power which it can deliver to any external circuit will be ............. $watt$View Solution
- 3The voltage drop across $15\, \Omega$ resistance in the given figure will be $.....V.$View Solution
- 4If power in external resistance $R$ is maximum thenView Solution
$(i) R = r$ $(ii)$ Power in $R$ is $\frac{{{E^2}}}{{4R}}$
$(iii)$ Input power $\frac{{{E^2}}}{{2R}}$ $(iv)$Efficiency is $50\%$
- 5A potentiometer consists of a wire of length $4\, m$ and resistance $10 \,\Omega$. It is connected to cell of $emf$ $2\, V$. The potential difference per unit length of the wire will be ............ $V/m$View Solution
- 6Two bulbs one of $200$ $\mathrm{volts},$ $60$ $\mathrm{watts}$ and the other of $200$ $\mathrm{volts},$ $100$ $\mathrm{watts}$ are connected in series to a $200$ $\mathrm{volt}$ supply. The power consumed will be ................ $\mathrm{watt}$View Solution
- 7A platinum resistance thermometer has a resistance of $50\,\Omega $ at $20\,^o C$. When dipped in a liquid the resistance becomes $76.8\,\Omega $. The temperature coefficient of resistance for platinum is $\alpha = 3.92 \times {10^{ - 3}}\,^o C$. The temperature of the liquid is .............. $^o C$View Solution
- 8A student uses the resistance of a known resistor $(1 \,\Omega)$ to calibrate a voltmeter and an ammeter using the circuits shown below. The student measures the ratio of the voltage to current to be $1 \times 10^3 \,\Omega$ in circuit $(a)$ and $0.999 \,\Omega$ in circuit $(b)$. From these measurements, the resistance (in $\Omega$ ) of the voltmeter and ammeter are found to be close toView Solution
- 9In the circuit shown in figure, all cells are ideal. The current through $2 \,\Omega$ resistor is ............ $A$View Solution
- 10For a cylinder of radius $R$ current density $J =J_0 \frac{r}{R} $, where $J_0$ is a constant and $r$ is distance from axis. Calculate total currentView Solution