Physics

Problem

A nichrome wire is tested at two different temperatures. At

20^\circ\text{C}

a potential difference of

4\,\text{V}

produces a current of

0.8\,\text{A}

. At

100^\circ\text{C}

the same potential difference produces a current of

0.5\,\text{A}

. Calculate the approximate percentage change in resistance of the wire between

20^\circ\text{C}

and

100^\circ\text{C}

. a)

40\%

increase b)

40\%

decrease c)

60\%

increase d)

50\%

increase