# Which of the following is not equal to 1 mm?

1 mm means 1 millimeter, where milli stands for 10^{-3}.

## Answer: Only option a) i.e. 100 cm is not equivalent to 1mm.

Go through the explanation to understand the steps to the solution.

**Explanation:**

Given options:

a) 100 cm

b) 1/10 cm

c) 1/1000 m

d) 1/1000000 km

Using unit conversion table for length, we see that:

1mm = 10 cm

Thus, option (A) is not correct.

1cm = 10 mm. Thus, 1mm = 1/10 cm

Hence, option (B) is correct

1m = 1000 mm. Thus, 1mm = 1/1000 m

Hence, option (C) is correct.

1km = 1000 m = 100000 cm = 1000000 mm. Thus, 1mm = 1/1000000 km

Hence, option (D) is correct.