A bar of iron is 10 cm at 20°C. At 19°C it will be (a of iron = 11 x 10-6/°C)
A bar of iron is 10 cm at 20°C. At 19°C it will be (a of iron = 11 ´ 10-6/°C)
A bar of iron is 10 cm at 20o C. At 19o C it will be (a of iron = 11 X 10−6/o C)