Electrical Science

What is the correct SI unit for Length?

• mm

• cm

• m

• km

Answer explanation

The correct SI unit for length is the meter (m). It is the base unit in the International System of Units (SI), while mm (millimeter), cm (centimeter), and km (kilometer) are derived units.

What is the correct SI unit for time?

• minutes

• hours

• seconds

• days

Answer explanation

The correct SI unit for time is seconds. While minutes, hours, and days are commonly used, they are not the standard units defined by the International System of Units (SI). Seconds is the base unit for measuring time.

Kilograms is the SI unit for which quantity?

• weight

• gravity

• force

• mass

Answer explanation

Kilograms is the SI unit for mass, which measures the amount of matter in an object. While weight is related to mass, it is a force that depends on gravity. Therefore, the correct answer is mass.

Ampere is the SI unit for which quantity?

• Current

• Voltage

• Resistance

• Impedance

Answer explanation

Ampere is the SI unit for electric current, which measures the flow of electric charge. The other options—voltage, resistance, and impedance—are related but represent different electrical properties.

What is the correct SI unit for Potential Difference (AKA Electromotive Force)?

• Current

• Voltage

• Resistance

• Impedance

Answer explanation

The correct SI unit for Potential Difference, also known as Electromotive Force, is Voltage. It measures the difference in electric potential between two points.

What is the correct SI unit for Power?

• Hertz

• Kelvin

• Joules

• Watts

Answer explanation

The correct SI unit for power is Watts. Power measures the rate of energy transfer, and one Watt is defined as one Joule per second, making it the standard unit for this physical quantity.

Resistance is measured using which SI unit?

• Ohms

• meters

• Farads

• Henrys

Answer explanation

Resistance is measured in Ohms, which is the SI unit for electrical resistance. The other options, meters, Farads, and Henrys, measure different physical quantities such as length, capacitance, and inductance, respectively.

Electrical charge is measured using which SI unit?

• Ohms

• Ampere

• Volts

• Coulomb

Answer explanation

Electrical charge is measured in coulombs (C), which is the SI unit for electric charge. Other options like ohms, amperes, and volts measure resistance, current, and voltage, respectively, but not charge.

Which one of the following is an example of engineering notation?

• 27.2 x 10⁶

• 27.2 x 10⁴

• 2.72 x 10⁸

Answer explanation

Engineering notation uses powers of ten that are multiples of three. The correct choice, 27.2 x 10⁶, is in this format, while the others do not conform to this standard.

Which one of the following is an example of standard form?

• 27.2 x 10⁶

• 27.2 x 10⁴

• 272 x 10⁸

Answer explanation

The correct choice, 2.72 x 10^2, is in standard form because it has a single non-zero digit to the left of the decimal point and is expressed as a product of a number and a power of ten.