Resistance increases when:
a) radius decreases
b) length decreases
c) viscosity decreases
d) hematocrit decreases
e) none of these answers

a) Radius decreases

Explanation:

Resistance of any conductor is directly proportional to the length of the conductor and inversely proportional to its cross-sectional area.

So, in mathematical terms, the resistance is written as

= ρ

As we know, cross sectional area is related to the radius of the conductor so if the radius of the conductor is decreased, the cross-sectional area will also decrease.

And if the cross-sectional area will decrease, the resistance will increase.

Thus decreasing the radius, increases the resistance.

answer; i believe the correct answer is (a)0