Current Electricity Charging Discharging Of Capacitors Question 745

Question: In the figure ammeter $ A _{1} $ reads a current of 10mA, while the voltmeter reads a potential difference of 3V. What does ammeter $ A _{2} $ in mA read? The ammeters are identical, the internal resistance of the battery is negligible. (Consider all ammeters and voltmeters as non- ideal.)

Options:

A) 6.67mA

B) 3.12mA

C) 1.12mA

D) 5.14mA

Show Answer

Answer:

Correct Answer: A

Solution:

[a] $ R _{A}= $ resistance of ammeter $ \frac{4-V _{1}}{100}=\frac{V _{1}-1}{R _{A}}+\frac{V _{1}-0}{100} $ ?.(i) $ 1V-0V=( 10mA )R _{A} $

$ R _{A}=100\Omega $ ?.(ii)

$ \frac{4-V _{1}}{100}=\frac{V _{1}-1}{100}+\frac{V _{1}-0}{100} $ [By using eq. (1) and (2)]

$ V _{1}=(5/3),V $

$ \frac{v _{1}-1}{R _{A}},= $ (Current in ammeter (II))

$ \frac{(5/3)-1}{100}=6.67,mA $