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