Question

In a copper voltmeter experiment, the current is decreased to one-fourth of the initial value but it is passed four times the earlier duration. The amount of copper deposited will be
A. Same
B. One-fourth of the previous value
C. Four times the previous value
D. $\dfrac{1}{16}th$of the previous value

Answer 1

Hint: We know that voltmeter is a tool able to measure the potential differences generated among factors in an electric-powered circuit. In a circuit, the voltmeter is continually linked in parallel to the circuit.

Complete Step by Step Answer:
Electrochemistry is the subdiscipline of chemistry that deals with the study of the connection between voltage and chemical changes. Chemical reactions that involve the input or generation of electrical currents are known as chemical reactions.

A voltmeter is a scientific instrument that is used to measure the electrical charge (amount of electricity) through electrolytic action. A copper voltmeter is used to know the electrochemical equivalent of copper. The amount of copper deposited is:
$m=ZIt$
Electrochemical equivalent =Z
Current=I
Time through which current is passed=t

Mass of the substance deposited because of a current I exceeded via them for a time t, is given by
$m=ZIt\ldots \ldots (1)$

When a current is deceased because of a current to one-fourth of the initial value that is $I=\dfrac{1}{4}I$and it is passed for four times then the duration is $t=4t$
$\Rightarrow m'=Z\times \dfrac{1}{4}I\times 4t \\ $
 $\Rightarrow m'=ZIt\ldots \ldots (2) \\ $

On comparing equations and $2$ we get
$m'=m$
Hence, the correct option is A.

Note: The voltmeter and the voltmeter are exceptional electric devices. The voltmeter is the tool that measures the capacity drop in a circuit, while the voltmeter measures the quantity of electrical current that is involved in an electrolytic cell.