Electrical Theory And Generators

1. Voltage induced into a conductor by the expanding and collapsing of a magnetic field is...

Magnetism.

Reluctance.

Direct current.

Electromagnetic induction.

When a magnetic field expands or collapses around a conductor, it induces a voltage in the conductor. This phenomenon is known as electromagnetic induction. It is the process by which a changing magnetic field creates an electric current in a conductor. Therefore, the correct answer is electromagnetic induction.

Explanation

When a magnetic field expands or collapses around a conductor, it induces a voltage in the conductor. This phenomenon is known as electromagnetic induction. It is the process by which a changing magnetic field creates an electric current in a conductor. Therefore, the correct answer is electromagnetic induction.

2. A _____ is two or more elements combined in definite portions by chemical means to form another substance.

Mixture

Compound

Electrons

Element

(1-1) A compound is two or more elements combined in definite portions by chemical means to form another substance.

Explanation

(1-1) A compound is two or more elements combined in definite portions by chemical means to form another substance.

3. What is the difference between an open and a short?

An open causesresistance to decrease; a short causes resistance to increase.

Excessive current flow in an open circuit; no current flow in a shorted component.

No current flow in an open circuit; excessive current flow in a shorted component.

Minimum voltage development across the open component; maximum voltage development across the shorted component.

(1-19) A short causes an excessive amount of current flow, whereas an open stops current flow.

Explanation

(1-19) A short causes an excessive amount of current flow, whereas an open stops current flow.

4. A _____ is a combination of two or more substances without using a chemical reaction.

Element

Mixture

Compound

Electrons

(1-1) A Mixture is a combination of two or more substances without using a chemical reaction.

Explanation

(1-1) A Mixture is a combination of two or more substances without using a chemical reaction.

5. What are the factors that affect the resistance of a material?

Area, weight, and state of material.

Area, temperature, and type of material.

Temperature, weight, and state of material.

Temperature, type of material, and state of material.

(1-6) Several factors, such as material type, area, and temperature are used to determine the amount of resistance placed on a material.

Explanation

(1-6) Several factors, such as material type, area, and temperature are used to determine the amount of resistance placed on a material.

6. In an atom, what electrons contain the most energy?

The energy is shared equally by all electrons

Orbiting electrons

Valence electrons

K shell electrons

(1-2) Valence electrons contain the most energy.

Explanation

(1-2) Valence electrons contain the most energy.

7. The electrostatic field around a positive ion moves

Inward.

Outward.

Inward, then outward.

Outward, then inward.

(1-3) In a positive ion, the electrostatic field moves outwards.

Explanation

(1-3) In a positive ion, the electrostatic field moves outwards.

8. The electrostatic field around a negative ion moves

Inward.

Outward.

Inward, then outward.

Outward, then inward.

(1-3) In a negative ion, there are electrostatic fields that move inwards.

Explanation

(1-3) In a negative ion, there are electrostatic fields that move inwards.

9. In a series-parallel circuit, find RT if series resistor R1=7 ohms, and parallel resistor R2 and R3=8 ohms.

23 ohms

15 ohms

11 ohms

8 ohms

(1-12) In order to find RT start with the paralell branches to find the total resistance. Once reduced to to the equivalent of the series circuit, add it up with the other series branches to find the sum.

Explanation

(1-12) In order to find RT start with the paralell branches to find the total resistance. Once reduced to to the equivalent of the series circuit, add it up with the other series branches to find the sum.

10. What is the simplest form of matter?

Element

Mixture

Compound

Electrons

(1-1) An Element Is the simplest form of matter.

Explanation

(1-1) An Element Is the simplest form of matter.

11. What is the resistance in a circuit if the power rating is 40 watts and total current is 2 amps?

40 ohms

20 ohms

10 ohms

0.5 ohms

(1-9) To get Resistance in the circuit, you square the current to make a whole number, then you divide it by the power.

Explanation

(1-9) To get Resistance in the circuit, you square the current to make a whole number, then you divide it by the power.

12. Atoms having only four electrons are known as

Insulators.

Conductors.

Stable atoms.

Semiconductors.

(1-3) Atoms having only four electrons are known as semiconductors.

Explanation

(1-3) Atoms having only four electrons are known as semiconductors.

13. Atoms having only eight electrons are known as

Insulators.

Conductors.

Stable atoms.

Semiconductors.

(1-2) If the atom has eight electrons in its outermost shell, it is stable.

Explanation

(1-2) If the atom has eight electrons in its outermost shell, it is stable.

14. Atoms having more than four electrons, but less than eight are known as

Insulators.

Conductors.

Stable atoms.

Semiconductors.

(1-3) Atoms having more than four electrons, but less than eight are known as insulators.

Explanation

(1-3) Atoms having more than four electrons, but less than eight are known as insulators.

15. Convert 500 milliamps to standard amperage.

.005 amps

.05 amps

.5 amps

50 amps

(1-8) Milli is the decimal equivalent of .001

Explanation

(1-8) Milli is the decimal equivalent of .001