Is Voltage Across Always a Magnitude?

  • Thread starter Thread starter pyroknife
  • Start date Start date
  • Tags Tags
    Magnitude Voltage
AI Thread Summary
Voltage across a resistor can be considered a magnitude in DC circuits, as it is scalar. In AC circuits, however, voltage includes both magnitude and phase angle, indicating its polarity. Therefore, when asked to find the "voltage across" a resistor, it is not just a magnitude but a signed magnitude. Understanding the context of the circuit type is crucial for accurate interpretation. Voltage is fundamentally a scalar quantity in DC, but it gains complexity in AC scenarios.
pyroknife
Messages
611
Reaction score
4
"Voltage across" a magnitude?

If a problem says to find the "voltage across" a resistor, is that always a magnitude?
 
Physics news on Phys.org


I may be wrong here but from what I remember from school,

in DC circuits, voltage is scalar.

in AC circuits, the voltage will have an associated phase angle with it.
 


There is polarity associated with that voltage.
 


pyroknife said:
If a problem says to find the "voltage across" a resistor, is that always a magnitude?

It is a signed magnitude.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculating the voltage across capacitors and resistors with switches
Replies
2
Views
727
Finding an open-cicuit voltage, why is resistor in series ignored?
Replies
2
Views
1K
A circuit involving two non-linear resistances (incandescent lamps)
Replies
14
Views
2K
Understanding example in Wikipedia entry for open circuit voltage
Replies
3
Views
2K
Can the Voltage Across a Capacitor Be Greater Than the Source Voltage in a Series RLC Circuit?
Replies
3
Views
1K
Connecting a number of EMF sources in a circle to form a circuit
Replies
9
Views
1K
Reading of Ammeter for this circuit with Voltage Controlled Resistors
Replies
9
Views
1K
Ohm's Law - Finding Source Voltage
Replies
3
Views
1K
Voltage-resistance graph for this circuit with a variable resistance
Replies
4
Views
631
How to Calculate Energy Stored in an Inductor?
Replies
16
Views
3K

Hot Threads

Recent Insights

Back
Top