Question

Two resistances are connected in series as shown in the diagram:

1. What is the current through the 5 ohm resistance?
2. What is the current through R?
3. What is the value of R?
4. What is the value of V?

Answer 1

Given: Potential difference across the 5 Ω resistor (V₁) = 10 V

Potential difference across the unknown resistor R (V₂) = 6 V

i. Current through 5 ohms resistance:

By using Ohm’s law:

I = `V/R`

I = `0/5`

I = 2 A

ii. Current through R:

The components are wired in series. Current stays the same in series.

∴ The current through R is 2A.

iii. Value of R:

By using Ohm’s law:

I = `V/R`

R = `V/I`

R = `6/2`

R = 3 Ω

iv. Value of total voltage (V):

Series voltage adds up across resistors.

V = 10 + 6

V = 16 V

∴ The total voltage is 16 V.