Physics Past Questions and Answers

Heat

I. is a form of energy
II. is measured with a thermometer
III. cannot be created or destroyed
IV. from a hot object is transferred through conduction only. Which of the statements above are correct?

A I and II only
B I and III only
C I, II and III only
D II, III and IV only
E I, II, III and IV

Question 202:

A car travels with a constant velocity of 45 kmh^-1 for 20s. What distance does it cover in this time?

A 0.025m
B 0.250m
C 2.500m
D 25.000m
E 250.000m

Question 203:

When the same amount of current, I is passed through different wires under the same conditions, the rates of production of heat are ____________

A Directly proportional to I
B Directly proportional to the resistances of the wires
C Directly proportional to the square of the resistances of the wires
D Inversely proportional to I
E Inversely proportional to the resistance of the wires

Question 204:

A current flows in a series circuit containing a resistor, R, an inductor, L and a capacitor, C. Which of the following is true of the power dissipated in the circuit component(s)?

A The power dissipated in L is greater than zero
B The power dissipated in R is zero
C The sum of the power dissipated in L and C is equal to that in R
D The sum of the power dissipated in L and C is greater than in R
E The sum of the power dissipated in L and C is zero

Question 205:

Emission spectra are caused by ____________

A Kinetic energy of moving atoms
B Potential energy of an electron in an atom
C Transition of an electron from a higher energy level to a lower energy level
D Transition of an electron from a lower energy level to higher energy level
E Transition of excited protons in the nucleus.