Ohms Law
Ohms Law
We all have experienced the situation that when a torch is used for several weeks, its light becomes dim. We say that its cells have become weak.This means that the potential difference has droped to a smaller value because the chemicals have been used up in the chemical reactions. As the potential difference has dropped so less current flows through the bulb, and hence produces less light. So, we can say that the electric current passing through the circuit depends on the potential difference applied across it. The larger is the potential difference, the larger is the current. This relationship between potential difference and current was first discovered by a German physicist Georg Simon Ohm (1787-1854) and is stated by the law named after him
Ohm's Law states that the current passing through a conductor is directly proportional to the potential difference between its ends, provided the physical conditions such as temperature of conductor remain unchanged.
He further observed that as we increase the potential the current increases, so we can state that the
i.e., or
where R is a constant which is called resistance of the material.
Unit of resistance
The SI unit of resistance is ohm .
If I = 1 Ampere, V = 1 Volt, then R = 1 .
The resistance of a conductor is 1 ohm if a potential difference of 1 volt is produced across its ends when 1 ampere of the current flows through it.
The conductors, which obey the Ohms law are called the ohmic conductors or linear resistances. All metallic conductors (such as silver, aluminium, copper, iron , etc,) are the Ohmic conductors or linear resistances.
The conductors, which do not obey the Ohms law are called the non-Ohmic conductors or non-linear resistances. Examples are, diode valve, transistors, electrolyte, etc.
Illustration: A 5 V battery is connected to a 10 resistance. Calculate the amount of current flowing through the circuit.
Solution: It is given that
V = 5 V
R = 10
To find I =?
According to Ohm's Law
V = IR
Hence a current of 0.5 A flows through the circuit.
Two resistors of resistance (A) Use the Ohm's law, V=IR. (B) Determine the effective resistance ( (C) Determine the electric current by using the relation,
| |||
| Right Option : C | |||
| View Explanation | |||
According to ohm's law, under given physical conditions | |||
| Right Option : D | |||
| View Explanation | |||
What is the strength of current flowing through a 20 | |||
| Right Option : B | |||
| View Explanation | |||
Students / Parents Reviews [10]
A marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Archit Segal
7thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thIt was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
Cheshta
10thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Barkha Arora
10thAbhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
Om Umang
10thOne of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
Aman Kumar Shrivastava
10thBeing a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
Prisha Gupta
8thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thIt was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Eshan Arora
8thMy experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
