Why Does a Filament Light Globe Draw More Current Initially?

AI Thread Summary
The initial higher current draw in a filament light globe occurs because the resistance of the filament is temperature-dependent, leading to lower resistance when cold. As the filament heats up, its resistance increases, stabilizing the current. For vehicle headlights, connecting them in parallel is preferable since if one bulb fails, the others remain operational, unlike in a series connection where a single failure disrupts the entire circuit. The discussion emphasizes the importance of understanding electrical resistance and circuit configurations. Overall, proper wiring can enhance functionality and safety in electrical systems.
cseet
Messages
40
Reaction score
0
Hi there,

can anyone pls explain why
1. the current through a filament light globe is greater in the first few milliseconds after it is turned on before it reaches it's "steady" glow?

2. is it better to have headlights in a motos vehicle connected in parallel rather than in series?

greatly appreciated!
Cseet
 
Physics news on Phys.org
1. filliment resistance is temperature depentent.

2. In series one goes out both go out. In parallel they go out one at a time.


You do realize we have a homework help forum?
 
The resistance of an electrical conductor varies with it's temperature.

Wired in series, if one headlight failed, the current would no longer be conducted to the other headlight.
 


Hi there,

thanks for your help.

I now realized that there's a homework help section... I'm new to this forum. thanks again
cseet
 

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

Why do the headlights on the car become dim when the car is starting?
Replies
4
Views
2K
Final Temperature of a Lightbulb filament
Replies
5
Views
4K
Why Does the Filament Box in a CRT Electron Gun Have Multiple Pins?
Replies
12
Views
2K
Electricity: Which globe uses most energy?
Replies
1
Views
2K
Why Does a Lamp Light Up Slowly When Connected with a NTC Thermistor?
Replies
7
Views
4K
Expressing current through a circuit
Replies
3
Views
1K
Why Does Passing Current Heat Wolfram Filament in Light Bulb?
Replies
9
Views
3K
Light waves from a normal house hold globe effecting a dc circuit. Why?
Replies
21
Views
3K
How Does Connecting a Wire Affect Light Bulbs in an Inductive Circuit?
Replies
3
Views
2K
Calculating the Power Needed to Light NYC in the War of Currents
Replies
5
Views
3K

Hot Threads

Recent Insights

Back
Top