Physics 203-NYB-05 Laboratory

DC Circuits

1. Simple Circuits

  • The voltmeter must be connected in parallel.
  • The ammeter must be connected in series.
  • To measure resistance, the resistors must be taken out of the circuit.

For each of the circuits shown below:

(A)Measure the voltage across the power supply: V

(B)Measure the voltage across each resistor: V1, V2

(C)Measure the current coming out of the power supply: I

(D)Measure the current in each resistor: I1, I2

(E)Measure the resistance of each resistor using the ohmmeter: R1, R2

(F)Read the resistance of each resistor using the color bands: R1*, R2*

(G)Verify that Ohm's Law is satisfied through each resistor.

(H)Verify that the voltage rule is valid.

(I)Verify that the current rule is valid.

Circuit #1 Circuit #2

2. Complex Circuits

Circuit #3

  • The voltmeter must be connected in parallel.
  • The ammeter must be connected in series.
  • To measure resistance, the resistors must be taken out of the circuit.

For the circuit shown below:

(A)Measure the voltage across the power supply: V

(B)Measure the voltage across each resistor: V1, V2, V3

(C)Measure the current coming out of the power supply: I

(D)Measure the current in each resistor: I1, I2, I3

(E)Measure the resistance of each resistor using the ohmmeter: R1, R2, R3

(F)Compute the equivalent resistance of the circuit using R1, R2 and R3.

(G)Compute the equivalent resistance of the circuit using V and I.

(H)Calculate the currents I1, I2, I3flowing into each resistor using only the value of V measured in (A), the equivalent resistance calculated in (F) and the values R1, R2, R3.

(I)Use Kirchhoff’s laws to find the current in each resistor: I1, I2, I3. The known values are V, R1, R2, and R3 only (use the values obtained from your measurements of (C) and (E)).

(J)Compare the equivalent resistance values obtained in (F) and (G).

(K)Compare the currents I1, I2, I3 of parts (B), (H), and (I).

Circuit #4

  • The voltmeter must be connected in parallel.
  • The ammeter must be connected in series.
  • To measure resistance, the resistors must be taken out of the circuit.

For the circuit shown below:

(A)Measure the voltage across the power supply: V

(B)Measure the voltage across each resistor: V1, V2, V3, V4, V5

(C)Measure the current across the power supply: I

(D)Measure the current across each resistor: I1, I2, I3, I4, I5

(E)Measure the resistance of each resistor using the ohmmeter: R1, R2, R3, R4, R5