If the length of the potentiometer wire is increased while keeping the voltage c
Practice Questions
Q1
If the length of the potentiometer wire is increased while keeping the voltage constant, what will happen to the balance point when measuring a cell's EMF?
It will move to a longer length.
It will move to a shorter length.
It will remain unchanged.
It will become unstable.
Questions & Step-by-Step Solutions
If the length of the potentiometer wire is increased while keeping the voltage constant, what will happen to the balance point when measuring a cell's EMF?
Correct Answer: Balance point length will increase.
Step 1: Understand what a potentiometer is. It is a device used to measure the electromotive force (EMF) of a cell by comparing it to a known voltage.
Step 2: Know that the balance point is the point on the potentiometer wire where the voltage across the wire equals the EMF of the cell being measured.
Step 3: Realize that the voltage across the potentiometer wire is determined by the length of the wire and the total voltage applied to it.
Step 4: If you increase the length of the potentiometer wire while keeping the voltage constant, the voltage per unit length of the wire decreases.
Step 5: Since the voltage per unit length is lower, it will take a longer length of wire to reach the same voltage as the EMF of the cell.
Step 6: Therefore, the balance point will move further along the wire, meaning it will increase.
Potentiometer Principle – A potentiometer measures the EMF of a cell by balancing it against a known voltage, where the balance point is directly related to the length of the wire and the voltage applied.
Ohm's Law – The relationship between voltage, current, and resistance, which is relevant when considering how changes in wire length affect the balance point.
