State Ohm's law. Describe an activity to verify Ohm's law experimentally with the help of a circuit diagram. Also, draw the V-I graph and explain how resistance can be determined from it.

Q: State Ohm's law. Describe an activity to verify Ohm's law experimentally with the help of a circuit diagram. Also, draw the V-I graph and explain how resistance can be determined from it.

Statement of Ohm's Law\nOhm's law states that the electric current flowing through a metallic wire is directly proportional to the potential difference V across its ends, provided its temperature remains constant. Mathematically, $V \propto I$ or $V = IR$, where R is the resistance of the conductor. Experimental Verification\nTo verify Ohm's law experimentally, we set up a circuit containing a resistor $R$, an ammeter $A$ to measure current, a voltmeter $V$ to measure potential difference across the resistor, a battery, and a plug key $K$. Procedure: First, connect the circuit components as per the circuit diagram with a single cell in the circuit. Note down the reading of the ammeter (current, I) and the voltmeter (potential difference, V) connected across the resistor. Now, add one more cell in the circuit and record the readings of both the ammeter and voltmeter again. Repeat this process by increasing the number of cells in steps (using 3 cells and then 4 cells). Calculate the ratio of $V$ to $I$ for each set of readings. Observation: It will be observed that the ratio $V/I$ is nearly constant for all readings, which proves Ohm's law. V-I Graph\nWhen a graph is plotted between the potential difference (V) along the x-axis and current (I) along the y-axis, a straight-line passing through the origin is obtained. This straight-line nature of the graph confirms that current is directly proportional to the potential difference. Determination of Resistance\nThe resistance (R) of the resistor can be determined by finding the slope of the V-I graph. Since slope = $\frac{\Delta V}{\Delta I}$, the reciprocal of the slope of the I-V graph or the slope of the V-I graph directly gives the resistance value.

Question

Accepted Answer

Statement of Ohm's Law
Ohm's law states that the electric current flowing through a metallic wire is directly proportional to the potential difference V across its ends, provided its temperature remains constant. Mathematically, $V \propto I$ or $V = IR$, where R is the resistance of the conductor. Experimental Verification
To verify Ohm's law experimentally, we set up a circuit containing a resistor $R$, an ammeter $A$ to measure current, a voltmeter $V$ to measure potential difference across the resistor, a battery, and a plug key $K$. Procedure: First, connect the circuit components as per the circuit diagram with a single cell in the circuit. Note down the reading of the ammeter (current, I) and the voltmeter (potential difference, V) connected across the resistor. Now, add one more cell in the circuit and record the readings of both the ammeter and voltmeter again. Repeat this process by increasing the number of cells in steps (using 3 cells and then 4 cells). Calculate the ratio of $V$ to $I$ for each set of readings. Observation: It will be observed that the ratio $V/I$ is nearly constant for all readings, which proves Ohm's law. V-I Graph
When a graph is plotted between the potential difference (V) along the x-axis and current (I) along the y-axis, a straight-line passing through the origin is obtained. This straight-line nature of the graph confirms that current is directly proportional to the potential difference. Determination of Resistance
The resistance (R) of the resistor can be determined by finding the slope of the V-I graph. Since slope = $\frac{\Delta V}{\Delta I}$, the reciprocal of the slope of the I-V graph or the slope of the V-I graph directly gives the resistance value.

CBSE · Class 10 · Science · ElectricityState Ohm's law. Describe an activity to verify Ohm's law experimentally with the help of a circuit diagram. Also, draw the V-I graph and explain how resistance can be determined from it.

Experimental Verification\nTo verify Ohm's law experimentally, we set up a circuit containing a resistor $R$, an ammeter $A$ to measure current, a voltmeter $V$ to measure potential difference across the resistor, a battery, and a plug key $K$.

V-I Graph\nWhen a graph is plotted between the potential difference (V) along the x-axis and current (I) along the y-axis, a straight-line passing through the origin is obtained. This straight-line nature of the graph confirms that current is directly proportional to the potential difference.

Determination of Resistance\nThe resistance (R) of the resistor can be determined by finding the slope of the V-I graph. Since slope = $\frac{\Delta V}{\Delta I}$, the reciprocal of the slope of the I-V graph or the slope of the V-I graph directly gives the resistance value.