Question

(a) Nichrome wire of length l and radius ‘r’ has resistance of 10 Ω. How would the resistance of the wire change when : (i) Only length of the wire is doubled ? (ii) Only diameter of the wire is doubled ? why element of electrical heating devices are made up of alloys ?Justify your answer. (b) Why element of electrical heating devices are made up of alloys

Answer 1

Answer:

( 1) :- Resistance is directly proportional to lenght of conducter

Therefore if the lenght is doubled then the resistance will also get doubled.

(2) :- Resistance is inversly promotional to the area of cross section.

so if diameter is doubled the the area will increase 4 times. So, the resistance will decrease

(b):- Alloys are mixture of two or more metals. so their melting and boling points are high as compared to pure metal. Therefore the elements of electrical heating devices are made up of alloys.

Hope it helps!! please mark as brainliest