**1**

Start. An oscilloscope is connected to a sine ac supply voltage
as shown above. Use the graph to determine the maximum voltage *V*_{max}
and the effective voltage *V*_{eff}. By clicking in the graph
window You can read the voltage values. Also determine the frequency *f* of
the ac supply voltage* *by first determing the period *T* from the graph.
(Answer).

**2**

A resistor is connected to a sine ac supply voltage as shown above. Use the two graphs to determine the resistance of the resistor. You may click in the graph window to read values for voltage and current. (Answer).

**3**

Start. A resistor is
connected to a variable ac supply voltage as shown above. Use the slider to vary
the effective voltage. Determine the average power (*P*_{eff}
= *V*_{eff}^{.}*I*_{eff}), which is delivered
to the resistor, when the effective voltage is 17 V. The voltage is on the graph
given in volt and the current in ampere. (Answer).

Move on to AC - transformers