Which SI base unit and symbol are correctly matched?

Which of the following is a complete measurement?

Which derived unit is equivalent to metre per second?

Why were standard units introduced?

Which prefix represents 10^-9?

Which statement correctly describes a non-physical quantity?

A time interval of 2000 microseconds is equal to:

Which rounding rule applies when the first dropped digit is less than 5?

Which expression is written in proper scientific notation?

When rounding off, if the first dropped digit is greater than 5, the retained digit is:

When a decimal point is moved to the right to write a small number in scientific notation, the exponent is: