Recharging a battery when Lightbulb and TV are in parallel

In summary, the wife reads a book that uses a light bulb that has a resistance of 100Ω and is connected to a 100 V line while the husband watches a TV that draws 100 W of power. They do these actives for 200 mins. Power comes from a wind generator that charges batteries. The wind supplies 10 amperes at a voltage of 100 V.
  • #1
Jtwa
9
0

Homework Statement


In a household, the wife reads a book that uses a light bulb that has a resistance of 100Ω and is connected to a 100 V line while the husband watches a TV that draws 100 W of power. They do these actives for 200 mins. Power comes from a wind generator that charges batteries. The wind supplies 10 amperes at a voltage of 100 V.

How long must the wind blow to recharge the battery.

Homework Equations


V=IR
P= V2/r

The Attempt at a Solution


Modeled the circuit to have the light bulb and tv in parrallel. Using the power equation, the tv also has 100Ω of resistance which doesn't make to much sense to me.

Power is J/s so we know that 200 min is 12000s which tell us 1.2 MJ is required to charge the battery.
 
Physics news on Phys.org
  • #2
Think about W consumed and W generated, that may make it clearer for you. You don't need a circuit diagram to solve this. You are missing an equation for wind power - what is it? That is key to seeing the solution in the simplest way. Write three power equations -

TV Power =
Light Power =
Wind Power =

That should help.

I see two potential answers - one (trivial) answer assuming the wind is blowing while the appliances are drawing power, and a different answer assuming the wind only starts blowing after the appliances have been turned off.
 
  • Like
Likes Jtwa
  • #3
Grinkle said:
Think about W consumed and W generated, that may make it clearer for you. You don't need a circuit diagram to solve this. You are missing an equation for wind power - what is it? That is key to seeing the solution in the simplest way. Write three power equations -

TV Power =
Light Power =
Wind Power =

That should help.

I see two potential answers - one (trivial) answer assuming the wind is blowing while the appliances are drawing power, and a different answer assuming the wind only starts blowing after the appliances have been turned off.

Thank you for the response.

The missing equation is P=IV which helps us calculate the Wind Power

I've calculated the following:
TV Power = 100W
Light Power = 100W
Wind Power = 1000W

Since a watt is a J/s then the TV and Light require 2.4x106 J
Divide power required by wind power and we get 2400 s which is 40 minutes? Does that sound correct?
 
  • #4
40 mins is correct.

You can also get to same answer using
Energy out = Energy In
200W * 200mins = 1000W * 40mins

Ok so the Watt.min isn't an SI unit but that doesn't matter.
 
  • Like
Likes Jtwa

1. How does recharging a battery when lightbulb and TV are in parallel work?

When the battery is connected in parallel with the lightbulb and TV, the battery's positive terminal is connected to the positive terminals of both the lightbulb and TV, and the negative terminal is connected to the negative terminals of both devices. This allows the battery to supply power to both devices simultaneously.

2. Is it safe to recharge a battery when lightbulb and TV are in parallel?

Yes, it is safe to recharge a battery when it is connected in parallel with other devices. As long as the battery and devices are properly connected and the appropriate voltage and current levels are maintained, there should be no safety concerns.

3. Can I use any type of battery to recharge when lightbulb and TV are in parallel?

No, it is important to use the correct type of battery when recharging in parallel with other devices. The battery's voltage and current output should match the requirements of the devices it is powering. Using the wrong type of battery could damage the devices and potentially cause safety hazards.

4. How long does it take to recharge a battery when lightbulb and TV are in parallel?

The time it takes to recharge a battery when connected in parallel with other devices will depend on the capacity of the battery and the current being supplied. Generally, it will take longer to recharge a larger capacity battery compared to a smaller one.

5. Can I use the lightbulb and TV while the battery is recharging in parallel?

Yes, you can use the lightbulb and TV while the battery is recharging in parallel. However, it is important to monitor the battery's charging progress and ensure that the devices are not drawing more power than the battery is able to supply. If the battery becomes drained, it may not be able to power the devices, and it could potentially become damaged.

Similar threads

  • Introductory Physics Homework Help
Replies
4
Views
274
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
24
Views
4K
  • Introductory Physics Homework Help
Replies
12
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
15
Views
10K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
4K
Back
Top