Question

1. if electrons are bound very loosely to the nuclei of atoms making up a certain substance, that substance is a

a. conductor
b. insulator
c. semiconductor
d. superconductor

1. which statement is true regarding the diagram below?

a. the current is largest at (a)
b. the current is largest at (b)
c. the current is largest at (c)
d. the current is the same everywhere.

1. which physical quantity is measured in units of a.s?

a. current
b. voltage
c. charge
d. resistance

Explanation:

Question 21

In conductors, electrons are not tightly bound to the nucleus and can move freely. Insulators have electrons tightly bound. Semiconductors have a limited number of free electrons (less than conductors). Superconductors have zero electrical resistance below a certain temperature (not related to electron - nucleus binding in the way described here).

In a series circuit (the circuit in the diagram is a series circuit as there is only one path for current to flow), the current is the same throughout the circuit. Ohm's law \(I=\frac{V}{R}\) (where \(V = 1.5V\) and \(R=2\Omega\), \(I = 0.75A\) in this case), and in a series circuit, \(I_1=I_2=\cdots=I_n\).

• Current (\(I\)) is measured in amperes (\(A\)).
• Voltage (\(V\)) is measured in volts (\(V\)).
• Charge (\(Q\)) is given by the formula \(Q = I\times t\), where \(I\) is current (in \(A\)) and \(t\) is time (in \(s\)). So the unit of charge is \(A\cdot s\).
• Resistance (\(R\)) is measured in ohms (\(\Omega\)).

Answer:

A. Conductor

Question 22