## Questions and Answers

What is the direction of electron flow in a circuit?

from the negative terminal to the positive terminal

What is the unit of electric charge, and what is the charge of an electron?

coulombs, 1.6 × 10^(-19) coulombs

What is the relationship between voltage, current, and resistance according to Ohm's Law?

V = I × R

What is the effect of increasing voltage on current, assuming constant resistance?

Signup and view all the answers

What is the formula for electric power in terms of voltage and current?

Signup and view all the answers

What is the power dissipated by a 250-ohm resistor connected to a 9-volt battery?

Signup and view all the answers

What is the formula to calculate the power consumed by a circuit, given the voltage and current?

Signup and view all the answers

If a motor is using 50 watts of power and draws a current of 0.4 amps, what is the voltage across it?

Signup and view all the answers

What is the formula to calculate the voltage across a circuit, given the current and resistance?

Signup and view all the answers

If a light bulb consumes 1.8 watts of power, and the cost of electricity is 11 cents per kilowatt-hour, what is the approximate cost of operating the light bulb for a month?

Signup and view all the answers

What is the current flowing through a 5 kilo-ohm resistor, given that 12.5 coulombs of electric charge flow through it in 8 minutes?

Signup and view all the answers

What is the power consumed by a 5 kilo-ohm resistor, given that 12.5 coulombs of electric charge flow through it in 8 minutes?

Signup and view all the answers

## Study Notes

- Conventional current is the flow of positive charge from the positive terminal to the negative terminal, whereas electron flow is from the negative terminal to the positive terminal.
- Current is defined as the rate of charge flow, or charge divided by time (Δq / Δt), and its unit is the amp (1 amp = 1 coulomb per second).
- Electric charge is associated with the quantity of charged particles, and an electron has a charge of 1.6 × 10^(-19) coulombs, which is negative.
- Ohm's Law describes the relationship between voltage, current, and resistance, where voltage is the product of current and resistance (V = I × R).
- If the resistance is kept constant, increasing the voltage will increase the current, and increasing the resistance will decrease the current.
- The voltage and current are directly related, while the resistance and current are inversely related.
- Electric power is the product of voltage and current, and it can be expressed in three forms: P = V × I, P = I^2 × R, and P = V^2 / R.
- Power is measured in watts, and 1 watt is equal to 1 joule per second.
- A current of 3.8 amps flowing for 12 minutes results in a charge of 2736 coulombs passing through any point in the circuit.
- The number of electrons represented by this charge is approximately 1.71 × 10^22 electrons.
- A 9-volt battery connected to a 250-ohm resistor results in a current of 0.036 amps, or 36 milliamps.
- The power dissipated by the resistor is 0.324 watts, or 324 milliwatts.
- The power delivered by the battery is equal to the power dissipated by the resistor, which is 0.324 watts.
- A 12-volt battery connected to a light bulb drawing 150 milliamps of current results in an electrical resistance of the light bulb of 80 ohms.
- The power consumed by the light bulb is 1.8 watts.
- The cost of operating the light bulb for a month, given a cost of electricity of 11 cents per kilowatt-hour, is approximately 14 cents.
- A motor using 50 watts of power and drawing a current of 400 milliamps has a voltage across it of 125 volts.- Voltage of the motor is 125 volts.
- Internal resistance of the motor is 312.5 ohms, calculated using Ohm's Law (v = iR) with voltage 125 volts and current 0.4 amps.
- Two important equations in solving common problems are P = VI and V = IR.
- Electric charge flowing through a 5 kilo-ohm resistor is 12.5 coulombs in 8 minutes.
- Electric current is the rate of charge flow, calculated by dividing the change in electric charge by the change in time.
- 8 minutes converted to seconds is 480 seconds.
- Electric current flowing through the resistor is 0.026 amps or 26 milliamps, calculated by dividing the charge (12.5 coulombs) by the time (480 seconds).
- Power consumed by the resistor is 3.38 watts, calculated using the equation P = I^2R with current 0.026 amps and resistance 5 kilo-ohms.
- Voltage across the resistor is approximately 130 volts, calculated using the equation V = IR with current 0.026 amps and resistance 5 kilo-ohms.

## Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

## Description

Test your understanding of electric circuits, including electric current, voltage, resistance, power, and Ohm's Law. Practice problems and calculations to help you master the basics of electricity.