Circuitry exam

The permeability of air is ________.

1

Each branch in a four-branch parallel circuit carries 10 mA. If one of the branches opens, then the current in each of the other three branches equals ________.

10 mA

If four 100 W lamps are connected in parallel across a 120 V source, what is the total current?

3.33 A

In solving series-parallel circuits using Ohm's law, first solve for:

RT.

A formula that applies to a two-branch parallel circuit is ________.

I T = I R1 + I R2

As additional branch resistors are connected in a parallel circuit, ________.

I T increases and R T decreases

Which one of the statements below does NOT apply to the voltage induced into a wire when it is moved through a magnetic field?

It depends on the current flowing in the wire.

In solving series-parallel circuits, the last and easiest to solve for is:

PT.

The magnetic field around an electromagnet is produced by ________.

a current flowing through the winding

If two north magnetic poles are brought close to each other, ________.

a force of repulsion pushes them apart

The difference between a balanced and an unbalanced Wheatstone bridge is measured by:

a galvanometer.

If you measure a lower than normal total current in a parallel circuit, ________.

a resistor opened

A simple electric doorbell probably uses ________ to ring the bell.

an electromagnet

If some turns of wire are removed from an electromagnet, the magnetic field will ________.

be less than the original electromagnet

The most popular application for a parallel circuit in electronics is as a:

current divider.

The power dissipated by any branch of a parallel circuit ________.

depends on the voltage and value of the resistor

According to the maximum power transfer theorem, maximum power is delivered to any load when the load resistance is:

exactly equal to the source resistance.

Magnetic lines that are close to each other are said to have a high ________.

flux density

If you want to measure a load voltage with a DVM, connect the meter ________.

in parallel with the load

A short in one branch of a parallel circuit results in:

increased current flow.

The current through any branch of a parallel circuit ________.

is inversely proportional to the branch resistance

If a 2.2 kΩ resistor and a 3.3 kΩ resistor are connected in parallel, R T equals ________.

less than 2.2 kΩ

A tesla is a unit of ________.

magnetic flux density

Electromagnetic induction is best defined as the process by which a voltage is produced in a conductor when there is:

motion between the conductor and the magnetic field.

Hysteresis is a characteristic of magnetic materials wherein a change in magnetization:

occurs after the application of a magnetic force.

The Wheatstone bridge circuit is widely used to measure:

precise resistances.

The term reluctance in magnetic circuits is like the term ________ in electrical circuits.

resistance

The ________ electromagnet cannot be further magnetized.

saturated

A ________ is a type of electromagnetic device that has a movable iron core called a plunger.

solenoid

The principal difference between a solenoid and a relay is that:

solenoids do mechanical work, relays do electrical work.

The movable part of the relay is the:

the armature.

Permeability is ________.

the ease of a material to be magnetized

Faraday's law states that the voltage induced across a coil of wire is proportional to these two factors.

the number of turns in the coil and the rate of change of the magnetic flux

If the total current equals 0 A in a four-branch parallel circuit, the trouble is that ________.

the power supply is off