Question

finding current in parallel circuit when ammeter and 4 resistors are connected​

Answer 1

Answer:

1/R=1/R1+1/R2+1/R3+1/R4

Explanation:

R1=resistance of resistor 1

R2=resistance of resistor 2

R3=resistance of resistor 3

R4=resistance of resistor 4

R=Total resistance

Answer 2

When 4 resistors of resistances R₁, R₂, R₃ and R₄ are connected in parallel, the total resistance of the circuit is calculated by the formula

$\dfrac{1}{R_T} = \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dfrac{1}{R_3} + \dfrac{1}{R_4}\\\\\\\\\implies R_T = \left( \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dfrac{1}{R_3} + \dfrac{1}{R_4} \right) ^{-1}$

Let the p.d be V.

Then, by ohm's law, V = IR

or I = V/R

$\implies I = V \times \dfrac{1}{\left( \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dfrac{1}{R_3} + \dfrac{1}{R_4} \right) ^{-1}}\\\\\\\\\implies \boxed{I = V \times \left( \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dfrac{1}{R_3} + \dfrac{1}{R_4} \right)}$