Three resistors of resistances 2 Ω, 3 Ω & 4 Ω are combined in series what is the total resistance of the combination.

Question

a)Three resistors of resistances 2 Ω, 3 Ω & 4 Ω are combined in series what is the total resistance of the combination. 

b) If this combination is connected to a battery of emf 10V & negligible internal resistance obtain the potential drop across each resistor.

Answer 1

Given: R₁ = 2Ω , R₂ = 3Ω, R₃ = 4Ω, 

E = 10V,

a) In series combination effective resistance R₃ is given by

R_s = R₁ + R₂ + R₃ 

= 2 + 3 + 4 

= 9Ω

b) Current through the circuit

I = \(\frac{E}{R_s}\) = \(\frac{10}{9}\)

I = 1.11 A

∴ Potential drop across R₁ = I,

R₁ = 1.11 × 2 = 2.22 

= 2.22 Volts

Potential drop across R₂ = IR₂

= 1.11 × 3 = 3.33 

= 3.33 Volts

Potential drop across R₃ = IR₃ = 1.11 × 4 = 4.44 

= 4.44 Volts