2c-Energy and voltage in circuits

Question 1

What is electric current?

Answer 1

A: Electric current is the flow of electric charge in a circuit, measured in amperes (A).

Question 2

What is voltage (potential difference)?

Answer 2

A: Voltage is the energy transferred per unit charge across a component, measured in volts (V).

Question 3

What is resistance?

Answer 3

A: Resistance is the opposition to the flow of current, measured in ohms (Ω).

Question 4

What is Ohm’s Law?

Answer 4

A: Ohm’s Law states that the current through a conductor is directly proportional to voltage, provided the temperature remains constant.

V=IR

where:

V= voltage (V)

I= current (A)

R= resistance (Ω)

Question 5

How does current behave in series and parallel circuits?

Answer 5

Series circuit: Current is the same at all points.

Parallel circuit: Current splits between branches but total current is the sum of currents in each branch.

Question 6

How does voltage behave in series and parallel circuits?

Answer 6

Series circuit: Voltage is shared across components.

Parallel circuit: Voltage is the same across all branches.

Question 7

How do you calculate total resistance in series and parallel circuits?

Answer 7

Series circuit: Total resistance = sum of individual resistances.
Rtoptal = R1+R2+R3+…

-Parallel circuit: Total resistance is found using:
1/ R total = 1/R1 + 1/R2 +1/R3

Question 8

Practical: Investigating Ohm’s Law

Measuring Current and Voltage

Answer 8

Method: Connect a circuit with a variable resistor, ammeter, and voltmeter.

Observation: Measure current and voltage for different resistance settings.

Conclusion: Plot a V-I graph to verify Ohm’s Law.

Question 9

Practical: Investigating Ohm’s Law

Investigating Resistance in Series and Parallel Circuits

Answer 9

Method: Connect resistors in series and parallel, measuring total resistance.

Observation: Verify that resistance adds in series and decreases in parallel.