Two technicians are explaining basic electricity and electronics: Technician A says that when one resistor is open in a parallel circuit, all the current flow in the circuit is stopped. Technician B says that when resistance in a circuit stays constant, if the voltage is decreased, the current decreases. Which technician is correct? A. Neither Technician A nor Technician B B. Technician A only C. Both Technician A and Technician B D. Technician B only

The answer is

C. Both Technician A and Technician B are correct

First we need to assume they are talking about simple circuits, with the source and a resistor, at zero frequency.

If the resistor is left open, no current will flow through it, so the voltage drop against its terminals is zero. (Technician A)

Technician B applies Ohm's law,

V = I*R,

V is the voltage

I is the current

R is the resistance

If R remains constant, If the voltage decreases, the current will decrease too.