The resistance of a resistance thermometer has values 2.7Ω and 3.7Ω at 00C and 1000C respectively. The temperature at which the resistance is 3.1Ω is
300C
400C
600C
700C
Rt, R0, R100, are resistances of wire at t0C,00C,1000C then temperature is t=Rt−R0R100−R0×100 substitute the given values in above equation t=3.1−2.73.7−2.7×100 ⇒t=0.41×100 ⇒t=400C