Question

1. A resistor stamped with Red Red Black Orange Silver has what resistance?

A. 2203 ohms

B. 220,000 ohms

C. 22,000 ohms

D. 660 ohms

2. The resistance created when one coulomb of charge is forced through a 1.0 volt difference in one second is

A. 1ohm

B. 10 ohms

C. 0.001 ohm

D. 1.0 kiliohm

3. the specific material resistivity depends on what?

a. the type of metal

b. the density of the material

c. the cross sectional area of the wite

d. the number of free electrons

4. resistance is caused when the electric fields in atoms in a metal

A. oppose the flow of electrons

B. create magnetic fields

C.absorb hear

D. capture free electrons in a conductor

Answer 1

1)

we have been given color code for the resistance of  the resistor as,

RED RED BLACK ORANGE SILVER

first three color bands ( in our case it is RED RED BLACK ) correspond to significant figures in the value of resistance, ( first band RED corresponds to first significant digit , second band RED corresponds to second significant digit, third band RED corresponds to third significant digit )

the fourth band ( in our case BLACK ) corresponds to a decimal multiplier ( that this represents the number of trailing zeros after the significant figures given by first three bands ),

and the fifth band ( In our case SILVER ) corresponds to tolerance value in percentage ( that is it represents the range around the value given by first four bands within which the actual value of resistance lies )

In the table below I have ,

..	significant figures	multiplier	Tolerance
color bands from left to right as on the resistor	RED	RED	BLACK	ORANGE	SILVER
color code value	2	2	0

So, the value of resistance of resistor is,

that is,

So the correct option is,

B) 220,000 ohm

2)

As per the ohm's law the resistance    is given in terms of voltage and current  as,

___________________________________________ relation 1

current is given as rate of flow of charge as,

the given information that of charge passes through difference in time period of corresponds to

rate of flow of charge

that is,

we have been given,

So, using   and    in relation 1 we get the value of resistance as,

So the correct option is,

A) 1 ohm

3)

Resistance    of a material is inversely proportional to the cross-section area   ( in the direction perpendicular to which the current flows through the conductor ) of the material and directly proportional to length   of the material as,

The specific resistivity of the material is defined as only the proportionality constant between this proportionality,

so, the specific resistivity of the material does not depend on the physical dimensions of the material such as cross sectional area,

resistivity is inversely proportional to the charge carrier density that is the number density of free electrons,

and thereby it depends on the type of metal also, since with the type of metal the the parameters like above mentioned free electron density etc. change.

and it also depends on the density of material.

for example,

1) In semiconductors the density of doping material  increases the number of charge carriers and thereby reduces the resistivity,

2) In case of electrolytes increasing the density of charge carrying ions between electrodes increase the current through the electrolyte and thereby reduces the resistivity of electrolytes,

so the correct options are,

a) , b) and d)

4)

by definition the value of resistance of a material tells us the degree to which the material opposes the flow of electrons ,

so  the correct answer is,

the resistance is caused when the electric fields in atoms in a metal oppose the flow of electrons.