Oscilloscope channel addition problem. Read the following oscilloscope settings carefully. Suppose you display a 1 kHz, 2 V sine wave in channel A and a DC, 1V signal in channel B with sensitivities set on 1V/div. You select 'Add' so that the two signals are combined and you readjust the position so the trace is in the middle of the screen. If you switch the signal in channel B from DC to AC, what will happen