Voltage Divider Circuit

The resistance R3 represents the internal resistance of a voltmeter. As an exercise try using a value of R3= 1MOhm (High internal resistance) followed by R3= 20 Ohm (Low internal resistance).. What effect will these values of have on the voltage and current flowing through the resistance R1? Will these voltages and currents increase or decrease? Explain the effects of loading in this circuit