Question

When a certain amount of violet light and yellow light shine on a metal surface, only violet light produces an electric current. Write 3 - 4 sentences describing how an increase in the intensity of each type of light will affect the amount of current produced. How does quantization help to explain these observations?

Answer 1

this phenomenon is called the photoelectric effect

so there are two factors of light that affect the ejection of electrons from the metal: intensity and frequency

frequency determines whether electrons will be ejected or not (only high enough frequency light ejects electrons; if the frequency is too low, then no electrons are ejected regardless of intensity)

intensity determines the rate at which electrons will be ejected

Answer 2

with that being said:

- how does changing the intensity of violet light change the current?
- how does changing the intensity of yellow light change the current?

Answer 3

notice how current increases as intensity increases, but only if the frequency is high enough

Answer 4

- how does changing the intensity of violet light change the current?
increases
- how does changing the intensity of yellow light change the current?
increses

Answer 5

hint: going back to the original problem

"only violet light produces an electric current. "

Answer 6

- how does changing the intensity of violet light change the current?
increases
- how does changing the intensity of yellow light change the current?
Does not

Answer 7

good

and as for the quantization part, the reason why only violet light produces current is that light is quantized, and only photons with the right amount of energy (the right quanta) can eject a particle

Answer 8

uh it's kinda hard to describe the shape but you gotta draw the field lines pointing north to south
like this

Answer 9

so all these lines?

Answer 10

yeah something like that, make sure the arrows are pointing in the right direction (north to south)

then for the force, I guess you could say the force at any location between the two magnets follows the direction of the field line, north to south

Answer 11

anyway for the last part of the question you just need to decide which two electric charges produce similar field lines, ex. two positives or two negatives or one positive one negative

Answer 12

one positive and one negative?

Answer 13

good, or to be more specific, one proton one electron; electron has to be on the left and proton on the right to produce the same field lines in the same direction

Answer 14

huh. what exactly are 1 and 2 representing?

I think(?) the resistors are still in series so total resistance is just the sum

Answer 15

36

Answer 16

12 is the voltage so it cannot be added to the resistors

Answer 17

24

Answer 18

good, that's it I believe (units are ohms)

Answer 19

okay so using this same diagram :

c. In the circuit diagram above, meters 1 and 2 are connected as shown. Write 2 - 3 sentences identifying each type of meter and how it is connected with the 8 Ω resistor.

d. In the circuit diagram above, predict which resistors will stop working (if any) when the switch is opened. Write 2 - 3 sentences explaining your reasoning.

Answer 20

c: well there are two types of meters, an ammeter and voltmeter, any ideas which is which? as a hint the ammeter must be in series with the resistors and the voltmeter must be in parallel

Answer 21

series so ammeter

Answer 22

is the ammeter meter 1 or meter 2?

Answer 23

1

Answer 24

meter 1 is in parallel with the resistor :(

Answer 25

2?

Answer 26

yeah, the ammeter must be meter 2 meaning the voltmeter is meter 1

Answer 27

okay so for part d

Answer 28

no

Answer 29

I Have @Vocaloid

Answer 30

uh so have you given any thought to it yet? there are only a few possibilities, either they both keep working, they both stop working, or only one keeps working

Answer 31

one stops working?

Answer 32

why do you say that?

Answer 33

actually all of them

Answer 34

they all stop working because they are in a series?

Answer 35

that's correct. Because the resistors are in series if either one of them fails, there is no closed path for current to go through any of them, so both stop working.

Answer 36

A light wave moves through glass (n = 1.5) at an angle of 15°. What angle will it have when it moves from the glass into air (n = 1)?

Answer 37

Do you remember snell's law?

Answer 38

No

Answer 39

is it the n1 equation. I think ?

Answer 40

yeah. so
\(\Huge \frac{\sin \theta_1}{\sin \theta_2}=\frac{n_2}{n_1}\).
Well actually i don't know the critical angle but i'm pretty sure we use snell's law cause pretty sure refraction and not reflection occur.

Answer 41

sin15/sin(theta)=1/1.5

theta=1.03

Answer 42

your first equation is correct, but i'm not sure how you're getting theta=1.03

Answer 43

oh 0.67?

Answer 44

could you show your work?

Answer 45

0.39?

Answer 46

I think I got it now

Answer 47

might be a degrees/radians issue?

Answer 48

Yeah it is. You've given the correct number in radians but you need to convert to degrees or use the correct mode on whatever calculator you're using

Answer 49

22.35

Answer 50

yup you're well on your way to design a spectrophotometer, all you need is to learn about dispersion now :)