A heating element using nichrome connected to a 230 V supply draws an initial current of 3.2 A which settles after a few seconds to a steady value of 2.8 A. What is the steady temperature of the heating element if the room temperature is `27^(@)C` ? Temperature coefficient of resistance of nichrome averaged over the temperature range involved is `1.70xx10^(-4) C^(-1)`.

Options

A. `680^(@)C`
B. `51^(@)C`
C. `920^(@)C`
D. `750^(@)C`

Answer

B

Explanation

`R_(27)=(V)/(I)=(230)/(3.2),R_(theta)=(230)/(2.8)`
`(R_(27))/(R_(theta))=(R_(0)(1+alphaxx27))/(R_(0)(1+alphaxxtheta))`