# Five resistors are connected in a circuit as shown. Find the ammeter reading when circuit is closed.

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Five resistors are connected in a circuit as shown. Find the ammeter reading when circuit is closed.

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Labelling each of the resistance as shown in the figure below.

Resistance R1 and R2 are in series

⇒ Rs1 = R1 + R2

⇒ Rs1 = 3 + 3 = 6Ω

Now Rs1 and R3 are in parallel.

⇒ $\frac{1}{R_p}=\frac{1}{R_{s1}}+\frac{1}{R_3}$

⇒ $\frac{1}{R_p}=\frac{1}{6}+\frac{1}{3}$

⇒ $\frac{1}{R_p}=\frac{1+2}{6}+\frac{3}{6}$

⇒ Rp$\frac63$ = 2

⇒ R= 2Ω

Now R4, Rp and R5 are in series.

⇒ Req = R4 + R5 +Rp

⇒ Req = 0.5 + 2 + 0.5 = 3Ω

Hence the Equivalent resistance of the circuit is 3Ω.

Current (I) = $\frac{V}{R}=\frac33$ = 1A

Hence the current reading in ammeter is 1A.