gorilla_08
Badges: 12
Rep:
?
#1
Report Thread starter 4 weeks ago
#1
https://youtu.be/MTx3PG5e1xk?list=PL...WkM0AQS&t=1224

The last question here, did he get part 2 wrong?

Isnt the resistor R meant to have changed its resistance, because it now has 3.6v rathher than 2v like it did in Q1.

If so, how would I work out this new resistance in R for Q2
0
reply
gorilla_08
Badges: 12
Rep:
?
#2
Report Thread starter 4 weeks ago
#2
why did he say 'this is staying at 1.5k ohms'?

Isn't a resistor in a potential divider meant to get a different resistance, if the voltage changes?
0
reply
blackugo
Badges: 18
Rep:
?
#3
Report 4 weeks ago
#3
No he didn't make a mistake
0
reply
blackugo
Badges: 18
Rep:
?
#4
Report 4 weeks ago
#4
Why would the resistor change its resistance? Resistance of the normal should be constant as far as I am aware.
Last edited by blackugo; 4 weeks ago
0
reply
gorilla_08
Badges: 12
Rep:
?
#5
Report Thread starter 4 weeks ago
#5
(Original post by blackugo)
Why would the resistor change its resistance? Resistance of the normal should be constant as far as I am aware.
i get it now, i thought as voltage across resistor in potential divider drops, the resistance drops. But this is only true for variable resistors or thermistors etc
0
reply
blackugo
Badges: 18
Rep:
?
#6
Report 4 weeks ago
#6
(Original post by gorilla_08)
i get it now, i thought as voltage across resistor in potential divider drops, the resistance drops. But this is only true for variable resistors or thermistors etc
The resistance doesn't drop because of the voltage. The voltage drops because of the resistance because the p. d is shared in the ratio of the resistances.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

What do you want most from university virtual open days and online events?

I want to be able to watch in my own time rather than turn up live (195)
29.77%
I want to hear more about the specifics of the course (109)
16.64%
I want to be able to dip in and dip out of lots of different sessions (58)
8.85%
I want to meet current students (55)
8.4%
I want to meet academics and the people that will be teaching me (51)
7.79%
I want to have a taster lecture or workshop to see what the teaching is like (128)
19.54%
My parents/guardians are more interested than me to be honest (38)
5.8%
Other things – I'll tell you in the thread (21)
3.21%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise