A voltmeter is also a device that shows the voltage difference across its termin

Question

A voltmeter is also a device that shows the voltage difference across its terminals, but it has a very large resistance. The next few problems show why.

D. Suppose instead, the voltmeter were in parallel with the resistor as shown in the figure at the right.

- If the system is connected up to a 12 V battery, what would the voltage drop be across the meter? (Assume you can ignore the internal resistance of the battery.)

- What is the voltage drop across the 50 ? resistor? Is this voltmeter giving a good measure of the voltage drop across the 50 ? resistor? Explain why or why not.

- Is this voltmeter giving a good measurement of what the voltage would be across the resistor if the voltmeter weren't there?

Explanation / Answer

r=1/r1 +1/r2 = 1/50 +1/1500 =31/1500 .............. i=v/r =12/(31/1500) =18000/31 .................. v=ir =(18000/31)(50) =0.0206

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.