To plot the V-I characteristics of an SCR (Silicon Controlled Rectifier), you will need the following equipment:

A). SCR
B). Power supply
C). Resistor
D). Multimeter
E). Oscilloscope
F). Breadboard
G). Connecting wires

Here are the steps to follow:

1. Set up the circuit on a breadboard by connecting the SCR, resistor, power supply, and multimeter as shown in the circuit diagram.
   
2. Turn on the power supply and adjust it to the desired voltage level. Measure the voltage using a multimeter.
   
3. Gradually increase the voltage while measuring the current through the SCR using the multimeter. Note down the values of voltage and current.
   
4. Repeat step 3 for different voltage levels, recording the corresponding current values.
   
5. Plot the recorded values on a graph, with voltage on the x-axis and current on the y-axis. This will give you the V-I (voltage-current) characteristic curve of the SCR.
   
6. You can also use an oscilloscope to observe the behavior of the SCR in response to different voltage levels. Connect the oscilloscope across the SCR to observe the waveform of the voltage and current.
   
7. Note any interesting observations such as the forward and reverse blocking voltage, the forward and reverse breakover voltage, and the holding current of the SCR.
   
8. Analyze the plotted V-I characteristics to understand the behavior of the SCR under different voltage levels and currents.
   
9. Make sure to disconnect the power supply and other equipment once you have completed the experiment.