Physics Exam 2015 : MC Questions 16 - 30

QUESTION 16
The transfer of heat is normally from an object or area at high temperature to an object or area at lower temperature. This phenomena ceases when both objects or areas are at the same temperature. This state is a state of
A. phase change.
B. thermal vaporization.
C. thermal fusion.
D. thermal equilibrium.
E. thermal expansion .

QUESTION 17
The mass number of an element is the number of
A. electrons.
B. protons.
C. neutrons.
D. protons and electrons.
E. protons and neutrons.

QUESTION 18
Which of the following types of radiation is more massive?
A. gamma
B. positron
C. alpha
D. negatron E. beta 

QUESTION 20
Which statement best explains the main difference between mechanical waves and electromagnetic waves?
A. Electromagnetic waves travel as fast as mechanical waves.
B. Electromagnetics waves have a source as mechanical waves do not.
C. Electromagnetic waves can travel through vacuum as mechanical wave do not.
D. Electromagnetic have a high frequency than mechanical waves.
E. Mechanical waves travel faster than electromagnetic waves.

QUESTION 21
The bending of waves around obstacles is called _____________.
A. reflection
B. diffraction
C. refraction
D. interference
E. destructive interference
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QUESTION 23
The magnetic field lines of a wire carrying uniform current is
A.  circular centered about the wire.
B.  rectangular centered about the wire.
C.  square centered about the wire.
D.  straight and parallel to the wire.
E.  straight and perpendicular to the wire. 

QUESTION 25
A power grid line having a resistance of 2Ω is to be used to transmit 2000W of power. The power engineer has a choice of using current values from 1A – 10A. For minimum power loss which current should be used to transmit power?

A.  10 A
B.  1A
C.  2A
D.  5A
E.  7A

Note : Attempt the questions by commenting below. Then check your answers against the ones we provided below. 

ANSWERS

​16. D
17. E
18. C
19. B
20. C
21. B
22. D
23. A
24. C
25. B
26. E
27. D
28. C
29. C
30. D