Question

1. NA 103 A metallic coil connected to a 220 V supply, has a resistance of 110 Q (while hot). How long
will this coil take to heat 1 kg to water from 20°C to 70°C ? Assume that whole of heat produced by
the coil is taken up by waer.
(C.B.S.E.)
(Heat capacity of water = 4186 1kg C)​

Answer 1

we know,

H = V2/R x t

And, also H = mCpΔt

So, V2/R x t = mCpΔT

Therefore, t = mCpΔT x R/V2-

Cp for water = 4.186 J/(g.K)

t = 1000g x 4.186 x (70 - 20) x 110/(220)2

= 475.7 secs

= 7.92 minutes.

Answer 2

Answer:

Step-by-step explanation:

we know,

H = V2/R x t

And, also H = mCpΔt

So, V2/R x t = mCpΔT

Therefore, t = mCpΔT x R/V2-

Cp for water = 4.186 J/(g.K)

t = 1000g x 4.186 x (70 - 20) x 110/(220)2

= 475.7 secs

fuck you