Basic Physical Concepts

Question 1

The atomic number of an element is determined by:

 (a) the number of neutrons.
 (b) the number of protons.
 (c) the number of neutrons plus the number of protons.
 (d) the number of electrons.

Answer 1

a

Question 2

The atomic weight of and element is approximately determined by:

(a) the number of neutrons.
(b) the number of protons.
(c) the number of neutrons plus the number of protons.
(d) the number of electrons.

Answer 2

a

Question 3

Suppose there is an atom of oxygen, containing eight protons and eight neutrons in the nucleus, and two neutrons are added to the nucleus. What is the atomic weight.

(a) 8
(b) 10
(c) 16
(d) 18

Answer 3

a

Question 4

An ion:

(a) is electrically neutral.
(b) has positive electric charge.
(c) has negative electric charge.
(d) can have either positive or negative charge.

Answer 4

a

Question 5

An isotope:

(a) is electrically neutral.
(b) has positive electric charge.
(c) has negative electric charge.
(d) can have either positive or negative charge.

Answer 5

a

Question 6

A molecule:

(a) can consist of a single atom of an element.
(b) always contains two or more elements.
(c) always has two or more atoms.
(d) is always electrically charged.

Answer 6

a

Question 7

In a compound:

(a) there can be a single atom of an element.
(b) there must always be two or more elements.
(c) the atoms are mixed in with each other but not joined.
(d) there is always a shortage of electrons.

Answer 7

a

Question 8

An electrical insulator can be made a conductor:

(a) by heating it.
(b) by cooling it.
(c) by ionizing it.
(d) by oxidizing it.

Answer 8

a

Question 9

Of the following substances, the worst conductor is:

(a) air.
(b) copper.
(c) iron.
(d) salt water.

Answer 9

a

Question 10

Of the following substances, the best conductor is:
  ( a) air.
   (b) copper.
   (c) iron.
   (d) salt water.

Answer 10

a

Question 11

Movement of holes in a semiconductor:

(a) is like a flow of electrons in the same direction.
(b) is possible only if the current is high enough.
(c) results in a certain amount of electric current.
(d) causes the material to stop conducting.

Answer 11

a

Question 12

If the material has low resistance, then:

(a) it is a good conductor.
(b) it is a poor conductor.
(c) the current flows mainly in the form of holes.
(d) current can flow only in one direction.

Answer 12

a

Question 13

A coulomb:

(a) represents a current of 1 ampere.
(b) flows through a 100-watt light bulb.
(c) is equivalent to 1 ampere per second.
(d) is an extremely large number of charge carriers.

Answer 13

a

Question 14

A stroke of lighting:

(a) is caused by a movement of holes in an insulator.
(b) has a very low current.
(c) is a discharge of static electricity.
(d) builds up between clouds.

Answer 14

a

Question 15

The volt is the standard unit of:

(a) current.
(b) charge.
(c) electromotive force.
(d) resistance.

Answer 15

a

Question 16

If an EMF of 1 volt is placed across a resistance of 2 ohms, then the current is:

(a) half an ampere.
(b) 1 ampere
(c) 2 amperes.
(d) impossible to determine.

Answer 16

a

Question 17

A backward-working electric motor, in which mechanical rotation is converted to electricity, is best described as:

(a) an inefficient, energy wasting device.
(b) a motor with the voltage connected the wrong way.
(c) an electric generator.
(d) a magnetic field.

Answer 17

a

Question 18

In a battery, chemical energy can sometimes be replenished by:

Answer 18

a

Question 19

A fluctuating magnetic field:

(a) produces an electric
(b) copper.
(c) iron.
(d) salt water.

Answer 19

a

Question 20

Visible light is converted into electricity

Answer 20

a