ES 1.3 & 1.9, E2 Study Guide

Which of the following is a formula for calculating total resistance in a parallel circuit?

1/RT=(1/R1) + (1/R2) + (1/R3)

*Which f the following is the correct formula for calculating total parallel inductive reactance in a parallel circuit?

1/XLT = (1/XL1) + (1/XL2) + (1/XL3) ...

An on-delay timer relay's contacts will not change states until:

A predetermined time has elapsed

To find the total resistance in a series circuit, you should:

Add the individual resistances

Which of the following is not a component of a time-delay relay?

Alarm

When the wire or foil strip inside a fuse melts, the fuse is said to be:

Blown

*One of the effects a capacitor has in a DC circuit is that it will:

Charge to a voltage equal to the source voltage

The difference between a fuse and a circuit break is:

Circuit breakers can be reset and used again

The Ohm's Law formula for calculating voltage is:

E=I*R

*The concept of a magnetic field being formed around a conductor when current flows through it is called:

Electromagnetism

*Capacitance is measured in:

Farads

*In an electric DC power supply, a capacitor is commonly used to:

Filter out the unwanted AC voltage

Which of the following is a type of circuit protection device?

Fuse

*Inductance is measured in:

Henrys

An example of using one limit switch to control multiple cylinders is the:

Hydraulic press

*The resistance provided by an inductor in an AC circuit is called:

Inductive reactance

*A coil that opposes any change in current flow is called a(n):

Inductor

*Which of the following is the correct formula for calculating total series inductance?

LT = L1 + L2 +L3 ...

When time-delay relays are used in time-driven sequencing, they basically take the place of:

Limit switches

The current that flows from the power supply and back to the power supply in a parallel circuit is called:

Main line current

Which is not an application of Ohm's Law?

None of the above

How many limit switches are needed if the cylinders to be synchronized are attached to the same machine member?

One

Which of the following is a formula for calculating power?

P = I*E

One machine that uses a time-delay relay to perform a cylinder dwell is a(n):

Plastic injection molding machine

The measure of energy consumed by a circuit is called:

Power

One reason why machines use multiple cylinders operating together is to:

Provide extra force

*Which of the following is not an example of an electromagnetic device?

Resistor

How are machines usually changed from automatic to manual mode?

Selector switch

In order to avoid seriously overheating the motor on a centrifugal air compressor at startup, it is recommended that:

The motor be unloaded when started

Kirchoff's Voltage Law or a series current says that the total voltage is equal to:

The sum of the voltage drops

Controlling two cylinders that are not attached to the same machine part requires:

Two limit switches