Electrical Engineering: Scientific Notation & Prefixes

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Questions and Answers

What is the scientific notation for the quantity 0.0005?

5.0 * 10-6

5.0 * 10-3

5.0 * 10-4 (correct)

5.0 * 10-5

Which prefix corresponds to a multiplier of 1,000,000,000?

Giga (G) (correct)

Kilo (k)

Mega (M)

Tera (T)

How is a negative power of ten used in scientific notation?

It moves the decimal point to the left. (correct)

It indicates a larger number.

It eliminates the need for prefixes.

It is always combined with a positive number.

If a resistance value is expressed as 470 kΩ, what is its equivalent in ohms?

470,000Ω Signup and view all the answers

Which of the following represents a power of ten that moves the decimal point four places to the right?

10^4 Signup and view all the answers

What is the scientific notation of 3,200,000?

3.2 * 10^6 Signup and view all the answers

Which of the following is a sub-multiple prefix for a factor of 1/1,000,000?

Micro (µ) Signup and view all the answers

What is the correct expression for a value of 30,000 in scientific notation?

3.0 * 10^4 Signup and view all the answers

What does a positive power value indicate according to the Passive Sign Convention?

The element is absorbing power. Signup and view all the answers

If an element releases power, what will be the sign of the power calculated?

-vi Signup and view all the answers

How is the power absorbed by an element expressed mathematically?

p = vi Signup and view all the answers

What is the unit used to measure electric power?

Watts Signup and view all the answers

What is the total power in a circuit at any instant according to the Law of Conservation of Energy?

Must balance the absorbed and supplied power. Signup and view all the answers

If a bulb with a rating of 100 watts operates at 120 volts, what is the expected current?

0.83 A Signup and view all the answers

What is the energy consumption of a 100-W electric bulb in two hours?

200 Wh Signup and view all the answers

What is the effect of current entering through the positive terminal of an element in terms of power?

The element is absorbing power. Signup and view all the answers

What characterizes an active element in an electrical circuit?

It can generate energy. Signup and view all the answers

Which of the following is an example of a passive element?

Inductor Signup and view all the answers

What type of source delivers power to the circuit without dependence on other circuit elements?

Independent voltage source Signup and view all the answers

What does an ideal independent current source do?

Maintains a designated current independent of voltage. Signup and view all the answers

Which symbol typically represents independent sources in circuit diagrams?

Arrow Signup and view all the answers

What type of dependent source is controlled by a current in another element?

Current-controlled voltage source Signup and view all the answers

What is a characteristic feature of the voltage-controlled voltage source (VCVS)?

It allows output voltage to vary based on an input voltage. Signup and view all the answers

Which of the following statements about passive components is correct?

They are not involved in providing power. Signup and view all the answers

What is the scientific notation for the number 200?

2.0 x 10^2 Signup and view all the answers

How is the number 0.00025 expressed in scientific notation?

2.5 x 10^-4 Signup and view all the answers

Which of the following numbers is expressed correctly in engineering notation?

33 x 10^3 Signup and view all the answers

What is the scientific notation for the number 5,000?

5 x 10^3 Signup and view all the answers

How is 0.00738 expressed in scientific notation?

7.38 x 10^-3 Signup and view all the answers

What is the proper scientific notation for the number 29,000,000?

2.9 x 10^7 Signup and view all the answers

If 9.12 x 10^3 is expressed as a regular decimal number, what is the result?

9120 Signup and view all the answers

What is the scientific notation for the number 0.000000597?

5.97 x 10^-7 Signup and view all the answers

When converting from a smaller unit to a larger unit, what direction should the decimal point move?

Left Signup and view all the answers

How many places do you move the decimal point when converting 0.15 mA to microamperes?

Three places to the right Signup and view all the answers

What is the correct conversion of 4,500 µV to millivolts (mV)?

4.5 mV Signup and view all the answers

Which of the following conversions requires moving the decimal point three places to the left?

47,000 pF to µF Signup and view all the answers

What is the result in milliamperes when you add 2,873 mA to 10,000 µA?

2,883 mA Signup and view all the answers

If you convert 0.00022 µF to picofarads (pF), how many pF will you have?

2200 pF Signup and view all the answers

Which of these conversions correctly reflects moving the decimal point three places to the right?

5,000 nA to µA Signup and view all the answers

Which is larger: 2000 pF or 0.02 μF?

0.02 μF Signup and view all the answers

Study Notes

Scientific Notation

Scientific notation expresses numbers as a product of a number (1 to 10) and a power of ten.
Example: 150,000 is 1.5 × 10^5, and 0.00022 is 2.2 × 10^-4.

Multiples and Sub-multiples

Electrical engineering involves a wide range of values where standard units can be expressed in simpler forms.
Example of resistance values can range from less than 0.01Ω to more than 1,000,000Ω.
Utilizing multiples and sub-multiples helps avoid excessive zeros in numeric representations.

Prefixes and their Multipliers

Tera (T): 1 × 10^12 (1,000,000,000,000)
Giga (G): 1 × 10^9 (1,000,000,000)
Mega (M): 1 × 10^6 (1,000,000)
Kilo (k): 1 × 10^3 (1,000)
None: 1 × 10^0 (1)
Centi (c): 1 × 10^-2 (1/100)
Milli (m): 1 × 10^-3 (1/1,000)
Micro (µ): 1 × 10^-6 (1/1,000,000)
Nano (n): 1 × 10^-9 (1/1,000,000,000)
Pico (p): 1 × 10^-12 (1/1,000,000,000,000)

Powers of Ten

Powers of ten are expressed as exponents (10^x), indicating decimal point movement.
Positive exponents move the decimal right; negative exponents move it left.
Example: 10^4 requires a right move of four places; 10^-4 requires a left move of four places.

Engineering Notation

Engineering notation allows one to three digits to the left of the decimal; exponents must be multiples of three.
Example: 33,000 is 33 × 10^3 in engineering notation, compared to 3.3 × 10^4 in scientific notation.

Metric Unit Conversions

Convert larger units to smaller units by moving the decimal point right; vice versa for smaller to larger.
Calculate the number of decimal places to move by finding the difference in the powers of ten.
Example: Converting from milliamperes (mA) to microamperes (µA) involves three places right due to a three-place difference.

Power and Energy in Circuits

Power (P) is defined as the rate of energy transfer, measured in watts (W).
Law of Conservation of Energy states that the total power in a circuit at any instant must equal zero.
Energy is measured in joules (J), with electric utilities often expressing it in watt-hours (Wh).

Passive and Active Components

Active elements generate energy; passive elements do not.
Passive components: resistors, capacitors, inductors.
Active components: generators, batteries, operational amplifiers, capable of delivering power.
Independent sources maintain constant voltage/current regardless of circuit conditions.

Dependent Sources

Dependent sources are influenced by other circuit elements, represented by diamond-shaped symbols.
Types include voltage-controlled and current-controlled sources.

Calculations and Examples

Calculate power using the formula P = VI (voltage times current).
Example: 100-watt light bulb calculation based on usage over time.

Current and Voltage

Current direction influences power sign; adheres to Passive Sign Convention.
Positive power indicates power absorption; negative indicates power supply by an element.

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Description

This quiz covers scientific notation, multiples and sub-multiples in electrical engineering, and the prefixes used for various measurements. Understand how these concepts simplify the representation of large and small values, and test your knowledge on powers of ten and their applications. Perfect for students in engineering and physics disciplines.