Waec Physics 2011 Past Questions and Answers

Question 41:

• WAEC 2011

The resistivity, \(\mathit{P}\), of a material of length l, cross-sectional area A, resistance R, is given by the equation

A. \(\mathit{P} = \frac{RA}{l}\)
B. \(\mathit{P} = \frac{l}{RA}\)
C. \(\mathit{P} = \frac{Rl}{A}\)
D. \(\mathit{P} = \frac{R}{Al}\)

Question 42:

• WAEC 2011

A wire of length 30cm is moved with a speed of 2ms^-1 at right angles to a magnetic field of flux density 0.4T. calculate the emf induced in the wire

A. 0.15V
B. 0.24V
C. 2.70V
D. 24.00V

Question 43:

• WAEC 2011

Which of the following practices will lead to losses in electrical power transmission?

A. Using transmission cables of large diameter
B. Transmitting at high voltage and low current
C. Transmitting at relatively low voltage and high current
D. Using a set-up transformer at the production end

Question 44:

• WAEC 2011

For photoelectric emission, the threshold frequency is the

A. Maximum frequency of incident radiation that will eject elecrons
B. Minimum fraquency of incident radiation required to eject elecrons
C. Frequency which results in the emission of the greater number of electrons
D. Fraquency whch impacts greatest kinetic energy to emitte electrons

Question 45:

• WAEC 2011

Which of the following properties is not applicable to X-rays? They

A. Travel in straight lines
B. Travel with the speed of light
C. Are deflected by magnetic field
D. Affect photographic films