pre-lab preparation sheet for lab 4—batteries, bulbs, and current

Look at Figure 4-8b and convince yourself that if the currents measured by current
sensors 1 and 2 are both positive, this shows that the current is in a clockwise direction
around all parts of the circuit.
Design measurements that will allow you to choose the model (or models) that best
describe the actual current through the circuit. (For example, to see if the current has a
different magnitude or direction at different points in the circuit [model B or model C in
Figure 4-6], you should connect two current sensors in various locations around the
circuit as in Figure 4-8b, to measure the current.)
Prediction 1-3: Use Table 4-1 to describe how the signs and magnitudes of the readings
of current sensor 1 and current sensor 2 in the circuit in Figure 4-8b would compare with
each other for each of the current models described in Figure 4-6.
Table 4-1
Model A
Model B
Model C
Model D
Sensor
CS1
CS2
CS1
CS2
CS1
CS2
CS1
CS2
Positive, negative,
or zero?
CS1 > CS2, CS1 < CS2,
or CS1 = CS2?
Activity 1-5: Developing a Model for Current in a Circuit
1. Be sure that current sensors 1 and 2 are plugged into the interface.
2. Open the experiment file called Current Model (L04A1-5). The two sets of axes that
follow should appear on the screen. The top axes display the current through sensor 1
and the bottom the current through sensor 2.
The amount of current through each sensor is also displayed digitally on the
screen.
3. Be sure to calibrate the sensors, or load the calibration. Zero the sensors befor they
are connected in the circuit.
Lab 04 – Batteries and Current