Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Electric Current in Conductors
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Electric Current in Conductors
A voltmeter's net resistance should be large in order to ensure that
A voltmeter's net resistance should be large in order to ensure that
Options
- Ait does not become overheated
- Bit avoids drawing excessive current
- Cit does not appreciably alter the potential difference being measured
- Dit can measure high potential differences
Correct answer
C. it does not appreciably alter the potential difference being measured
Step-by-step solution
A voltmeter is connected in parallel across the component whose potential difference is to be measured.
If the resistance of the voltmeter is not large, it will draw a significant amount of current from the main circuit. This reduces the current flowing through the component, thereby altering the potential difference across it.
To ensure that the voltmeter does not appreciably alter the potential difference being measured, its net resistance must be very large (ideally infinite).
If the resistance of the voltmeter is not large, it will draw a significant amount of current from the main circuit. This reduces the current flowing through the component, thereby altering the potential difference across it.
To ensure that the voltmeter does not appreciably alter the potential difference being measured, its net resistance must be very large (ideally infinite).