Physics Help ! electricity

[ailg1996]

The question is in the image . I need the method and Answers of the a and b parts. Thanks A lot

 

[scouserlfc]

this is easy Fuse X and Z remain safe while Fuse Y blows up as u see that rating of Fuse Z is higher even then the rating of the current flowing because of the kettle and therefore it doesnt blow while Fuse X is completely seperate as that current (the current because of Kettle) doesnt flow in Fuse X it remains safe and only Fuse Y blows up only and others remain okay.
Well this is what happens.
A).P=IV use this formula to get all the currents for the fuses and then add all the currents of X and Y to get Current of Z in fuse Z that is Hope u get it.
b). By above method ull find,
Fuse X=0.52A
Fuse Y=3.26A
Fuse Z =3.7

Well so u see that if even Fuse Y goes to 10 still the Fuse Z Current doesnt go above 15A while fuse X is completely different so only Fuse Y blows before other fuses are even blown.

 

[abcde]

I got the same answers as you scouserlfc but I was wondering that wouldn't the current in fuse Y and Z be the same since they are both on the live wire and are in series. Since current remains the same in series, shouldn't both fuse Y and Z have 3.7 A current flowing through them?

 

[ailg1996]

@scouser
I have the same question as @abcde
Shouldnt they be the same . . thts the confusing part. . . . .
I think both of them are 3.7 not 3.26

Oh k right (about the fuse)

 

[scouserlfc]

nopes that is the problem here as well but u see that the amount of total current flows through Fuse Z and the current splits i think this is a parrallel circuit as kettles and bulbs dont go together and they need switching on off so the amps split i think i would like to know the year of the question.

 

[abcde]

The kettle and the bulbs are definitely not in series! But fuse Y and Z are (see both are on the live wire..) so I think the current flowing through fuses Y and Z would be the same.

 

[ailg1996]

Its June 1998