Physics Past Questions and Answers

A platinum-resistance thermometer has a resistance of 5Î© at 0°C and 9Î© at l00°C. Assuming that resistance changes uniformly with temperature, calculate the resistance of the thermometer when the temperature is 45°C.

A 13.9 Î©
B 8.9 Ω
C 6.8 Î©
D 3.2 Î©
E 1.8 Î©

Question 487:

The linear expansivity of a metal P is twice that of another metal Q. When these materials are heated through the same temperature change, their increase in length is the same. Calculate the ratio of the original length of P to that of Q.

A 1:4
B 1:2
C 2:1
D 4:1
E 6:1

Question 488:

The pressure of a fixed mass of gas is 2.0 x 10⁵Nm^-2 at a known temperature. Assuming that the temperature remains constant, what will be the pressure of the gas if its volume is halved?

A 1.0x10⁵Nm^-2
B 2.0X10⁵Nm^-2
C 3.0x10⁵Nm^-2
D 4.0 x10⁵Nm^-2
E 5.0 x10⁵Nm^-2

Question 489:

Which of the following statements is not correct?

A Heat energy can be transformed into mechanical energy
B That total heat content of a body is the sum of the kinetic energies of its molecules
C Lf a body is heated, its molecules move faster.
D Lf a body is cooled, molecular movement remains constant.

Question 490:

A 400W immersion heater is used to heat a liquid of mass 0.5kg. lf the temperature of the liquid increases by 2.5^oC in one second, calculate the specific heat capacity of the liquid (Neglect heat losses to the surroundings)

A 80 Jkg^-1K^-1
B 320Jkg^-1K^-1
C 500Jkg^-1K^-1
D 1200J kg^-1K^-1
E 2000J kg^-1K^-1.