What word does this rebus represent?

meta meta
meta meta

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

If an electric train is travelling south, then which way is the smoke going?

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

A sundial has the fewest moving parts of any timepiece. Which has the most?

Which tank will fill first?