PLC Lesson 2: PLC Electrical Principles, Ratings, and Circuit Calculations

Which formula is used to calculate current in a series circuit

E divided by R

Using Ohm's Law, which formula is used to calculate voltage?

ET=IxR

Which formula is used to calculate voltage drop in parallel circuits?

Er= IxR

Which formula is used to calculate voltage drop of a load in series?

Er= IxR

Total current ? when loads are added in parallel.

INCREASES

Switches that use a(n) ? as the switching element are called current sink devices.

NPN transistor

Current sources use electron flow through a(n) ? .

PNP transistor

? is the amount of voltage consumed by an input device or output component as current passes through the object.

VOLTAGE DROP

The ? in a circuit containing series-connected loads is the same throughout the circuit.

current

The ? rating of PLC output circuitry is the amount of current the internal switches can safely handle when the load is first turned ON, when the load is operating, and when the load is turned OFF.

current

All ? sources have a positive and a negative terminal.

dc voltage

Several output components can be connected in series to PLC output modules.

false

When voltage levels are the same, a PLC may operate on either alternating current (AC) or direct current (DC).

false

mechanical contact switching device

n/o contact and open pushbutton

? at any point stops the flow of current.

opening a series circuit

? is the positive (+) or negative (-) state of an object's connections.

polarity

The total ? in a circuit containing parallel-connected loads is less than the lowest resistance value of any given load.

resistance

A ? is the negative power supply terminal of a DC-powered PLC.

sink

A current sourcing input uses the positive terminal of a DC-powered PLC as the source.

true

The voltage drop across each load is the same when loads are connected in parallel.

true

In a parallel-connected circuit, the ? across each load is the same when parallel loads are added or removed

voltage drop

Power is equal to ? .

voltage multiply by current