Statement - 1: The temperature dependence of resistance is usually given as $R = {R_0}\left( {1 + \alpha \,\Delta t} \right). The resistance of wire changes from 100\Omega to 150\Omega when its temperature is increased from {27^ \circ }C to {227^ \circ }C. This implies that \alpha = 2.5 \times {10^{ - 3}}/C.
Statement - 2: R = {R_0}\left( {1 + \alpha \,\Delta t} \right) is valid only when the change in the temperature \Delta T is small and \Delta T = \left( {R - {R_0}} \right) < < {R_0}.