PASCO SF-8616_8617 COILS SET - Manual (Page 7)

scientific 5
012-03800A
Experiment 1: Transformer Basics I
Introduction
When an alternating current passes through a coil of wire, it produces an alternating magnetic
field. This is precisely the condition needed for the electromagnetic induction to take place in a
second coil of wire. In this lab you will investigate several of the factors influencing the operation
of a transformer.
Equipment Needed - Supplied
1. The four coils from the PASCO SF-8616 Basic Coils Set
2. The U-shaped Core from the PASCO SF-8616 Basic Coils Set
3. Optional: the additional coils from the PASCO SF-8617 Complete Coils Set
Equipment Needed - Not Supplied
1. Low voltage ac power supply 0-6 VAC, 0-1 amp such as PASCO Model SF-9582
2. AC voltmeter 0-6 VAC
3. Banana connecting leads for electrical connections
Procedure
1. Set up the coils and core as shown in Figure
1. In the diagram, the coil to the left will be
referred to as the primary coil, and the one
to the right will be the secondary coil. Note
that we are putting in an alternating current
to the primary at one voltage level, and
reading the output at the secondary.
Iron Core
Primary Secondary Primary Secondary Primary Secondary
ac power
ac volts
Primary Secondary
Figure 1
2. With the 400-turn coil as the primary and the 400-turn coil as the secondary, adjust the input
voltage to 6 volts a.c. Measure the output voltage and record your results in Table 1.1.
3. Repeat step 2 after inserting the straight cross piece from the top of the U-shaped core.
Record your results. (See Figure 2.)
4. Repeat step 2 after placing the coils on the sides of the open U-shaped core. Record your
results.
5. Finally, repeat step 2 after placing the cross piece over the U-shaped core. Record your
results.
6. Using the core configuration which gives the best output voltage compared to input voltage,
try all combinations of primary and secondary coils. Use a constant input voltage of 6.0 volts
a.c. Record your data in Table 1.2.
Figure 2