Write ohm’s law. Describe the experiments showing ohm’s law and write its
conclusions.
Answers
Answer:
Ohm’s law: In the definite physical situation the electric current flowing through the conductor is directly proportional to the potential difference applied across it.
Experiment to prove Ohm’s law
For Ohm’s law, we make a circuit as shown above. The nichrome wire (conductor) is connected in series with a battery and an ammeter through a key. A voltmeter is connected in parallel between its two ends.
When the key is ON, current flows through the wire, which is measured by the ammeter. In addition, the potential difference developed across the ends of the nichrome wire is measured by the voltmeter. The readings are noted in the table given below.
Next, connect two batteries instead of one and again the magnitudes of current and voltage are noted.
Similarly the experiment is performed with three batteries and so on.
Observation table:
Number No. of batteries Voltage across two ends of wire (V) Current flowing through the wire (I) V/I
1 1
2 2
3 3
4 4
From the observation, a graph of I vs V is drawn which is a straight line passing through the origin.
Conclusions:
The electric current in the conductor increases proportionally with the increase in voltage.
I-V graph is a straight line.
The ratio of V and I remains constant every time.
The electric current in the conductor increases proportionally with the increase in voltage.
I-V graph is a straight line.
The ratio of V and I remains constant every time.
Explanation:
Ohm’s law: In the definite physical situation the electric current flowing through the conductor is directly proportional to the potential difference applied across it.
Experiment to prove Ohm’s law
For Ohm’s law, we make a circuit as shown above. The nichrome wire (conductor) is connected in series with a battery and an ammeter through a key. A voltmeter is connected in parallel between its two ends.
When the key is ON, current flows through the wire, which is measured by the ammeter. In addition, the potential difference developed across the ends of the nichrome wire is measured by the voltmeter. The readings are noted in the table given below.
Next, connect two batteries instead of one and again the magnitudes of current and voltage are noted.
Similarly the experiment is performed with three batteries and so on.
Observation table:
Number No. of batteries Voltage across two ends of wire (V) Current flowing through the wire (I) V/I
1 1
2 2
3 3
4 4
From the observation, a graph of I vs V is drawn which is a straight line passing through the origin.
Conclusions:
The electric current in the conductor increases proportionally with the increase in voltage.
I-V graph is a straight line.
The ratio of V and I remains constant every time.
The electric current in the conductor increases proportionally with the increase in voltage.
I-V graph is a straight line.
The ratio of V and I remains constant every time.
The electric current in the conductor increases proportionally with the increase in voltage.
I-V graph is a straight line.
The ratio of V and I remains constant every time.