Kirchhoff's Laws

What does Kirchhoff's second law show?

• conservation of charge

• conservation of energy

• In any closed loop, the sum of the e.m.f. is equal to the sum of the products of the current and the resistance (potential difference).

• The sum of the current entering a junction is the sum of the current leaving the junction.

Tags

NGSS.HS-PS2-5

Select the correct statement:

• The current in parallel resistors is always equal.

• The sum of the sources of EMF and volt-drops in a closed loop is zero.

• The sum of the currents in a closed loop is zero.

• The sum of the voltages at a node is zero.

The sum of all voltage drops in a series circuit equals the total applied voltage. This is know as what?

• Ohm's Law

• Kirchhoff's Voltage Law

• Kirchhoff's Current Law

• Bolen's Law

The total current in a parallel circuit equals the sum of the individual branch currents.

• Ohm's Law

• Kirchhoff's Voltage Law

• Kirchhoff's Current Law

• Bolen's Law

An electrical junction has three wires A, B and C connected to it. Wire A carries 4.2 A going in, wire B carries 2.6 A going out. What does wire C carry?

• 1.6 A going in

• 1.6 A going out

• 6.8 A going in

• 6.8 A going out

Analysis of a circuit produces two loop equations:

10x + 30y = 7 and 40x - 20y = 0

What are the currents x and y?

• x = 50 and y = 10

• x = 0.2 and y = 0.1

• x = 0.01 and y = 0.02

• y = 0.2 and x = 0.1

An electrical junction has four wires A, B, C and D connected to it. Wire A carries 7A going in, wire B carries 5 A going out and wire C carries 2 A going in. What does wire D carry?

• 10 A going out

• 5 A going out

• 4 A going in

• 4 A going out

Which statement is correct?

• The current in parallel resistors is always equal.

• The sum of the electric potential differences (or voltages) around a loop add to zero.

• The sum of the currents in a closed loop is zero.

• The sum of the voltages at a node is zero.

Is the potential at "B" higher or lower than "A's" potential? (for 3 points)

• "B" is higher than "A"

• "B" is lower than "A"

• Can't tell from the given information.

What is the magnitude of the current, I, traveling down through the center wire? ( for 3 points)

• 1/6

• 1/3

• 3/6

• 6/3