To analyze the statements regarding ammeters, we need to break down each statement and understand the principles behind them. Let's look at Statement I and Statement II individually before determining the best choice from the options provided.
Understanding Statement I
Statement I claims that "Higher the range, greater is the resistance of ammeter." This statement is generally true. An ammeter is designed to measure current, and its resistance plays a crucial role in how it operates. When you increase the range of an ammeter, you are essentially allowing it to measure higher currents. To do this without damaging the device, the internal resistance of the ammeter must also increase. This is because a higher resistance limits the amount of current that can flow through the ammeter, protecting it from excessive current that could cause damage.
Examining Statement II
Statement II states, "To increase the range of ammeter, additional shunt needs to be used across it." This statement is also true. A shunt is a low-resistance path that allows most of the current to bypass the ammeter. By adding a shunt, you can effectively increase the range of the ammeter. The shunt allows the ammeter to measure larger currents without exceeding its maximum rating, as it only measures a fraction of the total current flowing through the circuit.
Connecting the Dots
Now, let's evaluate the relationship between the two statements. While both statements are true, Statement II does not directly explain Statement I. Instead, they are related concepts in the context of ammeter functionality. Higher resistance is necessary for higher ranges, and shunts are used to achieve those higher ranges without damaging the ammeter.
Choosing the Correct Option
Based on our analysis:
- Statement I is true.
- Statement II is true.
- However, Statement II does not serve as a direct explanation for Statement I.
Therefore, the best choice among the options provided is:
(1) Statement – I is true, Statement – II is true, Statement – II is not the correct explanation of Statement – I.
This choice accurately reflects the truth of both statements while acknowledging that they are related but not directly explanatory of one another.
