Question

Hello everyone
please answer my questions....
1. How will you detect a weak current through any electrical circuit?
2. What happen to the deposition of hydrogen and oxygen during electrolysis,when electrodes are reserved?
3. Why zinc is electroplated on iron to make bridges and automobiles?

Answer 1

1. LED is a semiconductor device which glows even when a week current passes through it. There are two wires called leads attached to an LED.
2. Electrolysis, process by which electric current is passed through a substance to effect a chemical change. ... The process is carried out in an electrolytic cell (q.v.), an apparatus consisting of positive and negative electrodes held apart and dipped into a solution containing positively and negatively charged ions.
3. Zinc is electroplated on iron used to make bridges and automobiles. The coating prevents iron from rusting.

Answer 2

1) • By using a LED. Even when we pass a weak current, LED glows.

Lead pieces are attached to an LED.

One lead is longer than the other leads.

While connecting LED in the circuit, the long head is connected to the positive terminal of the battery in all cases.

• By using a compass:

Weak electric current flowing through a liquid can also be detected by using a compass.

We take out the cardboard tray from the inside of a discarded matchbox and place a small compass inside this cardboard tray.

2) Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.

When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode.

The reaction for decomposition of water into oxygen and hydrogen is as follows:
2H

2

O(l) -------> 2H

2

(g) + O

2

(g)

Thus, the number of hydrogen molecules produced is twice the number of oxygen molecules. So, electrolysis of water produces 2 volumes of hydrogen gas and 1 volume of oxygen gas because the ratio of hydrogen and oxygen elements in water is 2:1 by volume. Therefore, the amount of gases collected in two test tubes is not equal...

3) Iron used in bridges and automobiles is electroplated with a coating of zinc to protect it from corrosion and formation of rust....



Mark it as brainliest answer......!