Fundamental SI Units and Definitions

The video tutorial explains the definitions of SI-based units, including the meter, kilogram, second, ampere, kelvin, mole, and candela. Each unit is defined based on specific physical constants or phenomena, such as the speed of light for the meter, the mass of the international prototype for the kilogram, and the radiation of cesium atoms for the second. The ampere is defined by the force between conductors, the kelvin by the temperature of water's triple point, the mole by the number of entities in carbon-12, and the candela by luminous intensity of a specific frequency.

What is the definition of a meter based on?

• The length of a standard metal rod

• The circumference of the Earth

• The average length of a human foot

• The distance light travels in a vacuum in a specific fraction of a second

What is the kilogram defined by?

• The mass of the international prototype of the kilogram

• The weight of a liter of water

• The gravitational force on a standard object

• The mass of a cubic meter of air

How is a second defined in terms of cesium-133?

• The time it takes for the Earth to rotate 1 degree

• The average heartbeat of a human

• The duration of 9,192,631,770 periods of radiation from cesium-133

• The time it takes for light to travel one meter

What is the ampere defined by?

• The power output of a standard battery

• The charge of a single electron

• The current that produces a specific force between two parallel conductors

• The voltage across a standard resistor

What fraction of the thermodynamic temperature of the triple point of water is a Kelvin?

• 1/100

• 1/360

• 1/273.16

• 1/212

What does one mole represent?

• The number of molecules in a liter of water

• The mass of a single atom

• The number of atoms in 0.012 kg of carbon-12

• The volume of a gas at standard temperature and pressure

What is the frequency of the radiation used to define the candela?

• 540 * 10^12 Hz

• 600 * 10^12 Hz

• 500 * 10^12 Hz

• 580 * 10^12 Hz

Which unit is defined by the number of elementary entities in a system?

• Ampere

• Mole

• Kelvin

• Candela

What is the radiate intensity in the definition of the candela?

• 1/100 watt per steradian

• 1/1000 watt per steradian

• 1/683 watt per steradian

• 1/500 watt per steradian

Which of the following is NOT a base SI unit?

• Meter

• Liter

• Kilogram

• Second