An electric
conductor has the capacity to allow electric current pass through it. However,
the conductors don’t let all the energy pass through them. The property called
resistance decides how well a conductor can let the current pass through. The
more the resistance, lesser the conducting ability of a conductor.
In
the ncert solutions for class 10th Science chapter 12, you
get to know how electricity works. However, here, in this article, you can have
the knowledge of the factors that affect the resistance of a conductor.
1.
The material used in the wire
The
resistance of a wire is decided primly by the material used. Different
materials contain different concentrations of free electrons. These are the
electrons that are not bound to the atom. The conducting ability goes higher if
the wire material has a high number of free electron concentration. In other
words, the resistance stays low in good conductors having a high number of free
electrons.
2.
The length of the wire
During the
travel, the electrons suffer collisions in the conductor. These collisions take
out energy from them. The number of collisions increases with the increase in
the length of the wire. Hence, the resistance increases with the length and the
conducting ability decreases of a wire. So, if you take two wires of the same
material with different lengths, then the shorter one has less resistance. The
electrons have to give away more energy when they travel through the larger
pieces of the wire due to the excess number of collisions.
3.
The area of the cross section of the wire
The cross
section of a wire also affects the resistance. The large area of a thick wire
offers a larger cross section for the electrons to move easily. Hence the thick
wires have lesser resistance than the thin wires of the same material and the
same length. The increase in the area of the cross section of a wire decreases
its resistance and enhances the conductivity of electric current.
4.
The temperature of the wire
The
temperature also has the tendency to change the resistance of a conductor. This
happens due to the heat energy that the atoms of the conductor attain. The heat
energy goes in the conductor and increases the vibrations of the ions. The ions
start vibrating violently due to the availability of the excess energy. This
increases the overall collision counts during the flow of the current. More
collision results in more difficulty in the flow of the current. Hence, the
conductor’s resistance increases with the increase in the temperature.
So, when
you take the same length of a wire with the same length and cross section area,
the temperature will change the resistance. You can increase the temperature of
one wire in order to see how current flow in that wire gets slowed down.
Now you
know how the resistance changes in a conductor. If you desire in-depth
learning, focus on your study of the cbse class 10 Science Electricity. You should discuss the learning with the expert teachers
around you as well.
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