Voltage divider

  • #1

Main Question or Discussion Point

Very silly doubt....If say I had a voltage divider circuit with 2 equal Resistance say R applied between
1.V=5v and ground
2.V=5V and V=-5V
Whats the answers and what the difference?
I guess the answer for the 1 Q will be (5/2)...
Please explain the second ....Thank you
 

Answers and Replies

  • #3
What confuses me is then why is the negative terminal said to be connected to ground.
Shouldnt that mean the ground and -5v are at same potential
 
  • #4
davenn
Science Advisor
Gold Member
2019 Award
9,228
7,482
What confuses me is then why is the negative terminal said to be connected to ground.
Shouldnt that mean the ground and -5v are at same potential
depends on if its a single rail supply.....

+5V and GND (0V or negative line of power supply)

or a split supply where you have say.....

+5V, 0V, -5V where the 0V rail may be connectd to GND via the PSU case and mains earth


take a 12V battery, you have a + and - terminal --- from a circuit point of view the - terminal can be called 0V

now take a mains sourced 12V power supply, you have a +12V rail and a -(neg) 0V rail.
that negative rail may be floating ie. not connected to the case of the equip. Or it may be connected to the case and that case is also connected to GND via the Earth lead of the mains cable.

just a few random thoughts ;)

Dave
 
  • #5
sophiecentaur
Science Advisor
Gold Member
24,608
4,519
By stipulating a +5 and -5V supply, you are implying that there is a 'zero volts' somewhere in the power supplies, connected to ground which defines their voltages wrt ground.
 

Related Threads on Voltage divider

  • Last Post
Replies
15
Views
1K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
6
Views
3K
  • Last Post
2
Replies
31
Views
13K
  • Last Post
Replies
2
Views
6K
  • Last Post
Replies
13
Views
7K
  • Last Post
Replies
1
Views
4K
  • Last Post
Replies
5
Views
18K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
4
Views
2K
Top