Download App

Thermal and Chemical Effect of Current — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsThermal and Chemical Effect of Current2 Marks
Question
A brass plate having surface area 200cm2 on one side is electroplated with 0·10mm thick silver layers on both sides using a 15A current. Find the time taken to do the job. The specific gravity of silver is 10.5 and its atomic weight is 107.9 g/mol.
✓

Answer

I = 15A
Surface area = 200cm2,
Thickness = 0.1mm
Volume of Ag deposited = 200 × 0.01 = 2cm3 for one side
For both sides, Mass of Ag = 4 × 10.5 = 42g
$\text{Z}_{\text{Ag}}=\frac{\text{E}}{\text{F}}=\frac{107.9}{96500}$
$\text{m}=\text{ZIT}$
$\Rightarrow42=\frac{107.9}{96500}\times15\times\text{T}$
$\Rightarrow\text{T}=\frac{42\times96500}{107.9\times15}=2504.17\text{sec}=41.73\text{min}\approx42\text{min}$

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

Explore more

More "2 Marks Questions" from Thermal and Chemical Effect of Current→Thermal and Chemical Effect of Current — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

The magnetic field lines prefer to pass through iron than air. Explain why?
→
A point charge produces an electric field of magnitude 5.0NC-1 at a distance of 40cm from it. What is the magnitude of the charge?
→
Explain the root mean square value of alternating current.
→
Draw a plot of the binding energy per nucleon as a function of mass number for a large number of nuclei, 2⩽ A⩽240. How do you explain the constancy of binding energy per nucleon in the range 30 < A < 170 using the property that nuclear force is short - ranged?
→
Explain ground state and ionisation energy of hydrogen atom.
→
It is desirable that the standards of units be easily available, invariable, indestructible and easily reproducible. If we use foot of a person as a standard unit of length, which of the above features are present and which are not?
→
Write the relation for the forces $\overrightarrow{F}$ acting on a charge carrier q moving with a velocity $\overrightarrow{V}$  through a magnetic field $\overrightarrow{B}$  in vector notation. Using this relation, deduce the conditions under which this force will be (1) maximum (2) minimum.
→
Why the magnitude of drift velocity of metal electrons is very less?
→
The force on a north pole,$\overrightarrow{\text{F}}=\text{m}\overrightarrow{\text{B}},$ is parallel to the field $\overrightarrow{\text{B}}.$ Does it contradict our earlier knowledge that a magnetic field can exert forces only perpendicular to itself?
→
A 1cm object is placed perpendicular to the principal axis of a convex mirror of focal length 7.5cm. Find its distance from the mirror if the image formed is 0.6cm in size.
→