Question

How many bulbs of resistance 8 each should be connected in parallel combination to draw a current of 2 A from a battery of 4 V?

Answer 1

Given: Voltage (V) = 4 V

Current (I) = 2 A

Resistance of each bulb (R) = 8 Ω

By using the formula for total resistance:

R_total = `V/I`

= `4/2`

= 2 Ω

For n identical resistors in parallel:

R_eq = `R/n`

2 = `8/n`

⇒ n = `8/2`

n = 4

∴ The 4 bulbs should be connected in parallel.