Answer : The correct option is, (a) Gold
Solution :
As we know that,
.................(1)
where,
= mass of metal = 10 g
= mass of added water = 30 g
= final temperature = ?
= temperature of metal =
= temperature of added water =
= specific heat of water =
= specific heat of metal
Now we have to calculate the final temperature for all the given metals.
(a) For gold : given,
= specific heat of metal =
Change in temperature of water =
(b) For silver : given,
= specific heat of metal =
Change in temperature of water =
(c) For copper : given,
= specific heat of metal =
Change in temperature of water =
(d) For aluminium : given,
= specific heat of metal =
Change in temperature of water =
Therefore, the least temperature rise for water result in, Gold.