Army Group X Practice Set 1

(d)∵ R=ρ

l

A

R=

ρl×A

A×A

R=

ρV

A2

[∵l×A=V]
which implies R is inversely proportional to A2.
R inversely proportional to d4 , i.e
R∝

1

d4

If d reduces to

d

2

, then d4 reduces to

d4

16

R=16R
Hence, R increase sixteen times more