Question

Which has a higher resistance: a 50W -220V lamp or a 25W -220V lamp ? Calculate the ratio of the resistances.

Answer 1

R=V²/P

R₁=220*220/50

R₁= 968Ω

R₂=220*220/25

R₂=1936Ω

R₁/R₂ = 1936/968

R₁/R₂=2:1

from the formula P=V²/R

Since power is inversly proportional to resistance the bulb of 25W will offer greater resistance

Answer 2

here we go.. first we have to calculate the resistance then we have to take out the ratio