c
Resistance after temperature increases by  \(500\,{\,^o}C\,\,i.e.,\,{R_t}\, = \,\frac{V}{I}\, = \frac{{220}}{2}\, = 110\,\Omega \)  \(R_0 = 100\) (given) temperature coefficient of resistance, \(\alpha  = ?\) 

using \(R_t = R_0( 1 + \alpha t)\)

\(110 = 100 (1 + \alpha 500)\)

\(\alpha \, = \,\frac{{10}}{{100 \times 500}}\)  or, \(\alpha \, = \,2 \times {10^{ - 4}}\,\,{^o C^{ - 1}}\)