In the experiment of calibration of voltmeter, a standard cell of $e.m.f\,\,1.1\,volt$ is balanced against $440\,cm$ of potential wire. The potential difference across the ends of resistance is found to balance against $220\,cm$ of the wire. The corresponding reading of voltmeter is $0.5\,volt.$ The error in the reading of volmeter will be .................. $volt$
JEE MAIN 2014, Diffcult
Download our app for free and get started
In a voltmeter
$V \propto l$
$\mathrm{V}=\mathrm{k} l$
Now, it is given $\mathrm{E}=1.1$ $volt$ for $l_{1}=440\, \mathrm{cm}$ and $V=0.5$ $volt$ for $l_{2}=220\, \mathrm{cm}$
Let the error in reading of voltmeter be $\Delta \mathrm{V}$ then, $1.1=400\, \mathrm{K}$ and $(0.5-\Delta \mathrm{V})=220\, \mathrm{K}$
$\Rightarrow \frac{1.1}{440}=\frac{0.5-\Delta V}{220}$
$\therefore $ $\Delta V=-0.05 \text { volt }$
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
- 1View SolutionThe magnitude and direction of the current in the circuit shown will be
- 2A rod of length $l$ with thermally insulated lateral surface is made of a material whose thermal conductivity $K$ varies as $K = C/T$ , where $C$ is a constant. The ends are at temperatures $T_1$ and $T_2$ . The heat current density isView Solution
- 3An electric heater of resistance $6 \,ohm$ is run for $10$ minutes on a $120\, volt$ line. The energy liberated in this period of time isView Solution
- 4Forty electric bulbs are connected in series across a $220\, V$ supply. After one bulb is fused, the remaining $39$ are connected again in series across the same supply. The illumination will beView Solution
- 5If $X, Y$ and $Z$ in figure are identical lamps, which of the following changes to the brightnesses of the lamps occur when switch $S$ is closed?View Solution
- 6A potential difference of $V$ is applied at the ends of a copper wire of length $l$ and diameter $d$. On doubling only $d$, drift velocityView Solution
- 7$4$ bulbs marked $40\, W$, $250\, V$ are connected in series with $250\, V$ mains. The total power is ............. $W$View Solution
- 8The resistance of a rectangular block of copper of dimensions $2 \,mm \times 2 \,mm \times 5 \,m$ between two square faces is $0.02 \,\Omega$. What is the resistivity of copper?View Solution
- 9An electric bulb rated $50 \mathrm{~W}-200 \mathrm{~V}$ is connected across a $100 \mathrm{~V}$ supply. The power dissipation of the bulb is :View Solution
- 10The current $I$ in the given circuit will be $......A$View Solution
