SI Units and Conversions

What is the SI unit of mass?

• meter: m

• kilogram: kg

• gram: g

• pounds: lbs

Answer explanation

The SI unit for mass is the kilogram, not grams because most everyday objects are weighed in kilograms.

What is the SI unit for electric current?

• voltage: V

• ampere: A

• coulomb: C

• None of the above

Answer explanation

The ampere is the unit of electric current

Which represents the smallest measure of time?

• nanosecond

• millisecond

• microsecond

• picosecond

Answer explanation

There are 10^12 picoseconds in a second

10^9 nanoseconds in a second

10^6 microseconds in a second

10^3 milliseconds in a second

How many volts are in 1245 mV?

• 12.45 V

• 0.1245 V

• 1.245 V

• 1,245,000 V

Answer explanation

There are 1,000 millivolts in a volt, so to convert from millivolts to volts we divide by 1,000

Which of the following is NOT a unit in the SI system of units?

• kilogram
• second
• inch
• meter

What is the SI unit system primarily used for?

• Measuring time

• Evaluating temperature

• Calculating speed

• Standard for measurements

• How many hours are in 7,200 seconds? Hint: there are 3,600 seconds in 1 hour.

• 2.5 hours

• 1.5 hours

• 2 hours

• 3 hours

Answer explanation

There are 60 seconds in a minute, and 60 minutes in an hour, so there are 3600 seconds in an hour.

7,200 / 3,600 = 2

How many milliliters are in 4.5 L

• 4,500 mL

• 450 mL

• 45,000 mL

• 45 mL

Answer explanation

4.5 * 1000 = 4,500

How many bytes are in a kilobyte?

• 10

• 1,000

• 100

• Trick question - none of the above

Answer explanation

Computer memory uses powers of 2 rather than powers of 10 - think about which power of 2 (i.e. 2, 4, 8, 16, ...) is the closest to 1,000

How many bytes are in a kilobyte?

• 512

• 1,000

• 1,024

• 1,042

Answer explanation

2^10 = 1,024