P2 Electricity Flashcards
<p>What is <b>electrical current</b>?</p>
<p>Electrical Current is the flow of electrical charges</p>
<p>What is current measured in?</p>
<p>Current is measured in Amperes (A)</p>
<p>How do you calculate <b>flow of charge</b>?</p>
<p>Flow of Charge (C) = Current (A) x Time (s)</p>
<p>Q = It</p>
<p>What is an <b>Electrical Insulator</b>?</p>
<p>An electrical insulator is a material that doesn't allow electric currents to pass through it</p>
<p>What is an <b>Electrical Conductor</b>?</p>
<p>An electrical conductor is a material that allows electric currents to pass through it</p>
<p>Why can't electrical insulators conduct electricity?</p>
<p>Electrical Insulators have no free electrons</p>
<p>This means no charges are free to move and carry a current</p>
<p>What is <b>Potential Difference</b>?</p>
<p>Potential difference is the amount of energy that charge carriers have between two different points in a circuit</p>
<p>What is Potential Difference measured in?</p>
<p>Potential Difference is measured in Volts (V)</p>
<p>How do you calculate Potential Difference?</p>
<p>Potential Difference (V) = Current (A) x Resistance (Ω)</p>
<p>V = I x R</p>
<p>How do you calculate <b>Electrical Energy Transferred</b>?</p>
<p>Energy Transferred (W) = Potential Difference (V) x Charge (C)</p>
<p>E = V x Q</p>
<p>What variables effect the size of current?</p>
<ol><li>Resistance - If resistance increases, the current will decrease</li><li>Potential Difference - If the Potential Difference increases, the current will increase</li></ol>
<p>What is Resistance measured in?</p>
<p>Resistance is Measured in Ohms (Ω)</p>
<p>What is Power?</p>
<p>Power is the rate of energy transfer to a component</p>
<p>What is the size of current affected by?</p>
The size of current is affected by two things:
<ol><li>The resistance: If the resistance is increased, the current will decrease</li><li>The potential difference: If the potential difference is increased the current will increase</li></ol>
<p>How do you calculate resistance?</p>
<p>Resistance = Voltage/Current</p>
<p>R=V/I</p>
<p>What do you use to measure voltage?</p>
<p>Voltmeter</p>
<p>What do you use to measure current?</p>
<p>Ammeter</p>
<p>What is Ohm's Law?</p>
<p>Voltage = Current × Resistance</p>
<p>V=IR</p>
<p>Why does the I-V charicteristic of a bulb curve?</p>
<p>The I-V characteristic of a filament bulb curves because temperature rises. As temperature rises, so does resistance. As a result, the rate of increase of the current decreases and a greater change in the potential difference is required to cause a change in the current</p>
<p>How do you calculate electrical power?</p>
<p>Power = Current × Voltage</p>
<p>P = I × V</p>
<p>Power = Current2 × Resistance</p>
<p>P=I2R</p>
<p>How do you calculate Total Energy Transferred?</p>
<p>Energy Transferred = Power × Time</p>
<p>E = P × t</p>
<p>What are <b>Ohmic Conductors</b>?</p>
<p>Ohmic Conductors are conductors that obey Ohm's Law</p>
<p>The current through an Ohmic Conductor is directly proportional to the potential distance across as resistor</p>
<p>How do you calculate <b>Electrical Power</b>?</p>
<p>Power = current x Potential Difference</p>
<p>P = IV</p>
<p>Power = current2 x resistance</p>
<p>P = I2R</p>
<p>How do you calculate the total resistance of resistors in a series circuit?</p>
<p>Their total resistance is calculated by adding up the resistances of each individual resistor eg. R = R1 + R2 + R3 ...</p>