Waec Physics 2008 Past Questions and Answers

Question 31:

• WAEC 2008

a sound wave is produced fron a source ans an echo is heard t seconds afterwards. If d is the distance of the reflecting surface from the source, v the speed, p the wavelength and T the period of the wave, then

A. D = \(\frac{2t}{\lambda}\)
B. D = \(\frac{\lambda t}{2T}\)
C. D = \(\frac{2T}{\lambda t}\)
D. D = \(\frac{\lambda T}{2t}\)

Question 32:

• WAEC 2008

A negatively charged rod is held close to an uncharged metal ball on an insulating stand. The ball will

A. Be negatively chargeed
B. Be positively charged
C. Have an excess negatively charges on the side nearest the rod
D. Have an excess positively charges on the side nearest the rod

Question 33:

• WAEC 2008

Two bodies each carrying a charge of 2.00 x 10^-10C are 5cm apart. Calculate the magnitude of the force between the charges.[\(\frac{1}{4\pi \mathit{E}_o} = 9.00 \times 10^9 Nm^2C{-2}\)]

A. 1.44 x 10^-7N
B. 7.20 x 10^-9N
C. 7.20 x 10^-11N
D. 1.44 x 10¹¹N

Question 34:

• WAEC 2008

If the charge on an object is measured as 4.0 x 10^-18C, how many excess electrons does the object possess, given that the charge of an electron is 1.6 x 10^-18C

A. 18
B. 19
C. 25
D. 37

Question 35:

• WAEC 2008

Which of the following is a unit of the time rate of flow of electric charges?

A. Coulomb
B. Ampere
C. Volt
D. Watt