A metallic wire of uniform area of cross-section has a resistance
R, resistivity
ρ, and power rating
P at
V volts. The wire is uniformly stretched to reduce the radius to half the original radius. The values of resistance, resistivity, and power rating at
V volts are now denoted by
R′,
ρ′, and
P′respectively. The corresponding values are correctly related as __________.
Fill in the blank with the correct answer from the options given below