In a Potentiometer arrangement when a cell of EMF 1.2 volts is connec...
Explanation:
The potentiometer is a device used to measure the potential difference (EMF) of a cell accurately. It works on the principle of comparing the unknown EMF with a known EMF across a uniform wire.
Given:
EMF of the first cell (E1) = 1.2 volts
Null point length (l1) = 40 centimeters
Change in null point length (Δl) = 60 centimeters
Formula:
The EMF of a cell is given by the expression: E = (l1/Δl) * E1
Let's calculate the EMF of the second cell using the given data.
Calculation:
Step 1: Calculate the EMF of the second cell using the formula mentioned above.
E2 = (l1/Δl) * E1
E2 = (40/60) * 1.2
E2 = 0.8 volts
Explanation of the calculation:
The null point is the point on the wire where there is no potential difference. In the potentiometer arrangement, the null point occurs when the potential difference across the wire is balanced by the potential difference across the cell. When the first cell with an EMF of 1.2 volts is connected, the null point is obtained at a length of 40 centimeters.
When the second cell is connected, the null point shifts by 60 centimeters. This means that the potential difference across the second cell is equal to the potential difference across 60 centimeters of the wire.
Using the formula mentioned above, we can calculate the EMF of the second cell. By substituting the given values, we find that the EMF of the second cell is 0.8 volts.
Conclusion:
The EMF of the second cell is 0.8 volts. This indicates that the second cell has a lower EMF compared to the first cell.
In a Potentiometer arrangement when a cell of EMF 1.2 volts is connec...
apply the relation between emf and length i. e. E1/E2=L1/L2. And the ans. comes out to be 1.8V.