Question
The current in a conductor and the potential difference across its ends are measured by an ammeter and a voltmeter. The meters draw negligible currents. The ammeter is accurate but the voltmeter has a zero error (that is, it does not read zero when no potential difference is applied). Calculate the zero error if the readings for two different conditions are 1.75A, 14.4V and 2.75A, 22.4V.

Answer

Let the voltmeter reading when, the voltage is 0 be X.
$\frac{\text{l}_1\text{R}}{\text{l}_2\text{R}}=\frac{\text{V}_1}{\text{V}_2}$
$\Rightarrow\frac{1.75}{2.75}=\frac{14.4-\text{V}}{22.4-\text{V}}$
$\Rightarrow\frac{0.35}{0.55}=\frac{14.4-\text{V}}{22.4-\text{V}}$
$\Rightarrow\frac{0.07}{0.11}=\frac{14.4-\text{V}}{22.4-\text{V}}$
$\Rightarrow\frac{7}{11}=\frac{14.4-\text{V}}{22.4-\text{V}}$
$\Rightarrow7(22.4-\text{V})=11(14.4-\text{V})$
$\Rightarrow156.8-7\text{V}=158.4-11\text{V}$
$\Rightarrow(7-11)\text{V}=156.8-158.4\Rightarrow-4\text{V}=-1.6$
$\Rightarrow\text{V}=0.4\text{V}.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Consider a circular ring of radius r, uniformly charged with linear charge density $\lambda.$ Find the electric potential at a point on the axis at a distance x from the centre of the ring. Using this expression for the potential, find the electric field at this point.
Using Huygens’ Principle, draw a diagram to show propagation of a wavefront originating from a monochromatic point source. Explain briefly.
A narrow beam of singly$-$charged carbon ions, moving at a constant velocity of $6.0 \times 10^4\ ms^{-1},$ is sent perpendicularly in a rectangular region of uniform magnetic field $B = 0.5T$ It is found that two beams emerge from the field in the backward direction, the separations from the incident beam being $3.0\ cm$ and $3.5\ cm$. Identify the isotopes present in the ion beam. Take the mass of an ion $= A(1.6 \times 10^{-27})kg,$ where $A$ is the mass number.
Find the time period of the motion of the particle shown in figure Neglect the small effect of the bend near the bottom.
A card sheet divided into squares each of size 1 mm2 is being viewed at a distance of 9 cm through a magnifying glass (a converging lens of focal length 9 cm) held close to the eye.
(a) What is the magnification produced by the lens? How much is the area of each square in the virtual image?
(b) What is the angular magnification (magnifying power) of the lens?
(c) Is the magnification in (a) equal to the magnifying power in (b)? Explain.
An electron is projected horizontally with a kinetic energy of $10keV.$ A magnetic field of strength $1.0 \times 10^{-7}T$ exists in the vertically upward direction.
  1. Will the electron deflect towards the right or left of its motion?
  2. Calculate the sideways deflection of the electron while travelling through $1m$. Make appropriate approximations.
The half$-$life of $^{40}K$ is $1.30 \times 10^9y$. A sample of $1.00g$ of pure $\text{KCI}$ gives $160$ counts/ s. Calculate the relative abundance of $^{40}K\ ($fraction of $^{40}K$ present$)$ in natural potassium.
An empty plastic box of mass m is found to accelerate up at the rate of $\frac{\text{g}}{6}$ when placed deep inside water. How much sand should be put inside the box so that it may accelerate down at the rate of $\frac{\text{g}}{6}?$
Can $\text{L}_\alpha$ X-ray of one material have shorter wavelength than $\text{K}_\alpha$ X-ray of another?
In an experiment on photoelectric effect, the stopping potential is measured for monochromatic light beams corresponding to different wavelengths. The data collected are $11s$ follows:
wavelength $(nm)$ $350$ $400$ $450$ $500$ $550$
stopping potential$(V):$ $1.45$ $1.00$ $0.66$ $0.38$ $0.16$
Plot the stopping potential against inverse of wavelength $\big(\frac{1}{\lambda}\big) $ on a graph paper and find
  1. The Planck constant,
  2. The work function of the emitter and.
  3. The threshold wavelength.