Question about op amps?

[Peyter]

In the 741, what are NC and Null Offset (two pins of null offset) ?

 

[Peter Bennett]

In the 741, what are NC and Null Offset (two pins of null offset) ?

NC means "No Connection" - the pin is not connected inside the IC.

If you connect the two ends of a pot to the two offset null terminals,
and the wiper of the pot to the negative supply, you can adjust the
pot to remove any input offset voltage that the opamp generates.
(Short the input terminals, and adjust the pot for zero output
voltage.)

 

[Keith R. Williams]

NC means "No Connection" - the pin is not connected inside the IC.

Be careful. "NC" can also mean NOT-TO-BE-CONNECTED.

 

[Peyter]

NC means "No Connection" - the pin is not connected inside the IC.

If you connect the two ends of a pot to the two offset null terminals,
and the wiper of the pot to the negative supply, you can adjust the
pot to remove any input offset voltage that the opamp generates.
(Short the input terminals, and adjust the pot for zero output
voltage.)

I have another question then. I am looking at a board right here where
there is an LM324N with 4 op amp, two of which are unconnected.
Near that ic there is an LM741CN. Why would a 741 be used if
there are two available op amps in the LM324N. I assume that
the LM324N don't have null offsets because they are more modern, so
I don't really understand this, any ideas?