UPSEE 2018 Solved Paper

As we know, surface tension, S=

force

length

=

F

l

Hence, its SI unit is

N

m

.
So, option (a) is unit of surface tension.
Again, option (b)

joule

(metre )2

≅

energy

(length )2

=

force ×length

(length )2

force

length

=

F

l

In terms of SI unit, it will be

N

m

, hence it is also equal to surface tension.
Again, option (c)

kg

s2

≈

mass

(time )2

But

energy

(length )2

=

F×s

s2

=

m×a×s

s2

=m×

distance

(time )2

×

1

distance

=

kg

s2

=

F

1

Hence, option (c) also equivalent to surface tension.
But, option (d)=

watt

metre

=

power

mass

=

force ×distance

mass

=

N−m

kg

cannot be equal to surface tension.
Hence, option (d) is correct.