describe the construction, working and usefulness of a dry cell, with the help of a diagram
Answers
Electricity, as you probably already know, is the flow of electrons through a conductive path like a wire. This path is called a circuit. Batteries have three parts, an anode (-), a cathode (+), and the electrolyte. The cathode and anode (the positive and negative sides at either end of a traditional battery) are hooked up to an electrical circuit.
The chemical reactions in the battery causes a build up of electrons at the anode. This results in an electrical difference between the anode and the cathode. You can think of this difference as an unstable build-up of the electrons. The electrons wants to rearrange themselves to get rid of this difference. But they do this in a certain way. Electrons repel each other and try to go to a place with fewer electrons.
In a battery, the only place to go is to the cathode. But, the electrolyte keeps the electrons from going straight from the anode to the cathode within the battery. When the circuit is closed (a wire connects the cathode and the anode) the electrons will be able to get to the cathode. In the picture above, the electrons go through the wire, lighting the light bulb along the way. This is one way of describing how electrical potential causes electrons to flow through the circuit.
However, these electrochemical processes change the chemicals in anode and cathode to make them stop supplying electrons. So there is a limited amount of power availableElectricity, as you probably already know, is the flow of electrons through a conductive path like a wire. This path is called a circuit. Batteries have three parts, an anode (-), a cathode (+), and the electrolyte. The cathode and anode (the positive and negative sides at either end of a traditional battery) are hooked up to an electrical circuit.
The chemical reactions in the battery causes a build up of electrons at the anode. This results in an electrical difference between the anode and the cathode. You can think of this difference as an unstable build-up of the electrons. The electrons wants to rearrange themselves to get rid of this difference. But they do this in a certain way. Electrons repel each other and try to go to a place with fewer electrons.
In a battery, the only place to go is to the cathode. But, the electrolyte keeps the electrons from going straight from the anode to the cathode within the battery. When the circuit is closed (a wire connects the cathode and the anode) the electrons will be able to get to the cathode. In the picture above, the electrons go through the wire, lighting the light bulb along the way. This is one way of describing how electrical potential causes electrons to flow through the circuit.
However, these electrochemical processes change the chemicals in anode and cathode to make them stop supplying electrons. So there is a limited amount of power available in a battery.
A dry cell consists of a zinc container whose base acts as the negative electrode. The carbon rod placed at the centre with a brass cap which acts as the positive electrode. And this is surrounded by a mixture of manganese dioxide and charcoal in a muslin bag. The electrolyte that is uses is a moist paste of ammonium chloride. The outer body of the zinc container is insulated with cardboard.
When the dry cell is connected in a circuit comprising a bulb, current flows in the circuit due to the chemical reaction that takes place in the cell. This makes the bulb glow.
The dry cell is a primary cell and it cannot be recharged.
