Understanding Electric Current and Resistance

What is the unit of electric current?

• watt

• volt

• ampere

• ohm

What is the formula for calculating resistivity (ρ)?

• ρ = R / (A × L)

• ρ = A + (R / L)

• ρ = L / (R × A)

• ρ = R × (A / L)

How does resistance change with temperature according to the equation ρ = ρo (1 + α ΔT)?

• Resistance increases with temperature.

• Resistance remains constant regardless of temperature.

• Resistance decreases with temperature.

• Resistance is unaffected by changes in temperature.

What is the formula to calculate power (P) dissipated in a resistor?

• P = R / V

• P = V^2 / R or P = I^2 * R

• P = V * R

• P = V + I

How do you calculate electric energy consumption in joules?

• Energy (J) = Voltage (V) × Current (A)

• Energy (J) = Power (W) × Time (s)

• Energy (J) = Power (W) ÷ Time (s)

• Energy (J) = Power (W) + Time (s)

What does electromotive force (e.m.f) represent in a circuit?

• The total resistance in a circuit.

• The current flowing through the circuit.

• The voltage drop across a resistor.

• The energy provided per unit charge by a source in a circuit.

In a series circuit, how does the total resistance compare to individual resistances?

• The total resistance is greater than the individual resistances.

• The total resistance is equal to the sum of individual resistances.

• The total resistance is less than the smallest individual resistance.

• The total resistance is the same as the largest individual resistance.

What do Kirchhoff's rules help us analyze in electrical circuits?

• They assist in calculating power loss in transformers.

• They are used to design circuit layouts for printed circuit boards.

• They help analyze current and voltage in electrical circuits.

• They help determine the resistance in electrical circuits.

What is Kirchhoff's Current Law (KCL)?

• The sum of currents entering a junction equals the sum of currents leaving the junction.

• The power in a circuit is equal to the product of voltage and current.

• The total voltage around a closed loop is equal to zero.

• The current through a conductor is directly proportional to the voltage across it.

According to Kirchhoff's Voltage Law (KVL), what must be true about the voltages in a closed loop?

• The sum of the voltages must equal zero.

• The sum of the voltages must equal the total resistance.

• The sum of the voltages must equal the total current.

• The sum of the voltages must equal the power consumed.