Advanced Ohm's Law Applications
In Ohm's Law, what variable is held constant in a resistive linear element?
Electrical power is the product of these two quantities.
What are voltage and current?
The strength of a magnetic field is measured in this unit.
What is the tesla?
What happens in a conductor when it moves through a magnetic field?
What is an electric current is induced?
What distinguishes electric force from magnetic force?
What is electric force acts on charge at rest, magnetic force acts on moving charge?
A resistor has a voltage drop of 12 V across it and dissipates 24 W of power. What is the current?
What is 2 A?
What is the formula for electrical energy in terms of power and time?
What is E = P x t (Energy = Power x Time)?
How can the magnetic field around a wire be increased?
What is by increasing the current or coiling the wire?
The process of creating current from motion in a magnetic field is known as what?
What is electromagnetic induction?
Explain why parallel circuits are more reliable than series circuits.
What is each path operates independently, so others can function if one fails?
If a circuit contains resistors in both series and parallel, this rule is used to simplify total resistance.
What is equivalent resistance calculation?
How much energy (in joules) does a 100 W device use in 3 minutes>
What is 18,000 J?
What is the shape of the magnetic field around a straight current-carrying wire?
What are concentric circles?
A transformer changes the voltage of an alternating current using what principle?
What is mutual induction?
How can increasing resistance in a circuit actually increase safety?
What is it limits the current, reducing overheating and risk of fire?
Describe the effect of temperature on resistance in a typical metallic conductor.
What is resistance increases as temperature increases?
What is the significance of kilowatt-hours in energy billing?
What is it measures energy usage over time and determines electricity cost?
The right-hand rule is used to determine this property in electromagnetism.
What is the direction of the magnetic field?
Why doesn’t a transformer work with DC current?
What is because a changing magnetic field is required for induction?
Describe the difference in behavior of a compass near a wire with DC versus AC current.
What is steady deflection with DC, vibrating or fluctuating with AC?
A 60 W bulb operating at 120 V draws how much current, and what is the resistance?
What is 0.5 A and 240 Ω?
A toaster runs on 110 V and has a resistance of 10 Ω. How much energy does it use in 60 seconds?
What is 72,600 J?
In what configuration can a magnetic field be nearly uniform?
What is between the poles of a horseshoe magnet or inside a solenoid?
How does Lenz’s Law relate to energy conservation?
What is it ensures the induced current opposes the change, conserving energy?
In an electric motor, why does the armature need to rotate?
What is to continuously switch polarity and maintain motion due to magnetic interaction?