Question

If each resistor in the circuit shown is 5.0 Ω and the battery is 12.0 V, what does the first ammeter (A1) read? A. 0.12 V B. 0.48 V C. 0.96 V D. .24 V

Answer 1

Rt= R1+R4+R23

R23 = 5/2 = 2.5 Ω

Rt= 5+5+2.5= 12.5Ω

I = U/R = 12/12.5=0.96 A

Answer C, A not V

Answer 2

Answer:

The first ammeter reads 0.96 A.

Explanation:

From the attached figure,

Resistance of all resistors, R₁ = R₂ = R₃ = R₄ = 5 Ω

Voltage of the battery, V = 12 V

First we will find the total resistance of the circuit,

R₂ and R₃ are in parallel. So,

$\dfrac{1}{R_{23}}=\dfrac{1}{R_2}+\dfrac{1}{R_3}$

$R_{23}=2.5\ \Omega$

Now R₁, R₂₃ and R₄ are in series.

So, $R_{eq}=5+5+2.5$

$R_{eq}=12.5\ \Omega$

Now we have to find the current across the first ammeter.

$I=\dfrac{V}{R_{eq}}$

$I=\dfrac{12\ V}{12.5\ \Omega}$

So, I = 0.96 A

Hence, the correct option is (c) " 0.96 A"