Question

State Ohm's law. Draw a graph between voltage and current for a metallic conductor. Draw a circuit diagram of a circuit which consists of battery, ammeter, voltmeter, resistor, rheostat and a key.

Answer 1

Hint: To answer this question, we have to first define what ohm’s law is. After that we simply have to draw the voltage versus current graph for any metallic conductor that follows ohm's law. After that, we have to draw a simple circuit with a battery, ammeter, voltmeter, resistor, rheostat, and a key.

Complete answer:
Ohm’s law gives a relation between the current, resistance, and voltage in a circuit. According to ohm's law, the current flowing between two points is directly proportional to the voltage difference between those two points. This means more is the voltage difference, more is the current flow between these points. This can be represented as,
$ \Rightarrow V \propto I$
$ \Rightarrow V = IR$
Here $V$ is the voltage applied or the voltage difference across the two points, $I$ is the current supplied and $R$ is the resistance of the given wire or substance.
The $R$ or the resistance of the wire can be defined as an opposition to the flow of current or charge in the wire. The resistance for a particular material of a given length is always constant irrespective of the voltage supplied.

The above graph shows voltage versus current graph for a metallic substance with a resistance of $2\Omega $.

The above circuit diagram shows a battery, ammeter, voltmeter, resistor, rheostat, and a key connected in a circuit which is the required diagram.

Note: In a circuit, some aiding devices are used. For example, the ammeter and voltmeter help in measuring current and voltage across the circuit. Rheostat helps in varying the resistance hence the current in the circuit. The key makes a circuit complete in switched on position and breaks the circuit in off condition. The battery acts as a source of energy supply in a circuit.