Explain the construction and working of a dry cell.

थोडक्यात उत्तर

A dry cell is a portable form of a leclanche cell.
It consists of zinc vessel which acts as a negative electrode or anode.
The vessel contains a moist paste of saw dust saturated with a solution of ammonium chloride an chloride.
The ammonium chloride acts as an electrolyte.
The purpose of zinc pide is to maintain the moistness of the paste being highly gyroscopic.
The carbon rod covered with a brass cap is placed in the middle of the vessel. It acts as positive electrode or cathode.
It is surrounded by a closely packed mixture of charcoal and manganese dioxide (Mn0₂) in a muslin bag.
Here Mn0₂ acts as depolarizer. The zinc vessel is sealed at the top with pitch or shellac.
A small hole is provided in it to allow the gases formed by the chemical action to escape.
The chemical action inside the cell is the same as in avalanche cell.

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पाठ 2: Electricity - Evaluation [पृष्ठ ३४]

पाठ 2 Electricity
Evaluation | Q IX. 3. | पृष्ठ ३४

Select the correct alternative

In a torch, the source of electricity is

Describe the construction, working and usefulness of a dry cell, with the help of a diagram.

What is the direction of flow of current in a dry cell?

Mention two advantages of a dry cell.

Primary cells are used in mobile phones.

Write the differences between the primary cell and the secondary cell.

Choose the incorrect statement.

Figure A and B, show a bulb connected to a cell in two different ways.

What will be the direction of the current through the bulb in both the cases. (Q to P or P to Q)
Will the bulb glow in both the cases?
Does the brightness of the glowing bulb depend on the direction of current through it?

Fig. 12.10 A and B, show a bulb connected to a cell in two different ways.

Does the brightness of the glowing bulb depend on the direction of current through it?

Think of six activities which use electric current. Also name the devices used to perform the activity.