Waec Physics 2012 Past Questions and Answers

Question 46:

• WAEC 2012

Which of the following statements about X-rays is correct? X-rays

A. Are produced when a metal surface is irradiated with ultraviolet light
B. Are produced when a metal target is used to block fast miving electrons
C. Have long wavelengths and are therefoer very penetrating
D. Are not part of the electromagnetic spectrum

Question 47:

• WAEC 2012

Which of the following arrangements of radiations is in the order of decreasing penetrating power?

A. \(\alpha, \beta, \gamma\)
B. \(\alpha, \gamma, \beta\)
C. \(\gamma, \beta, \alpha\)
D. \(\beta, \gamma, \alpha\)

Question 48:

• WAEC 2012

Which of the following radiations emitted in radioactive decay has momentum, a fairly high penetrating power and is deflected by a magnet?

A. Alpha particles
B. Beta particle
C. Gamma radiation `
D. X-radiation

Question 49:

• WAEC 2012

A ray of light is incident on an air-glass boundary at an angle \(\theta\). If the angle between the partially reflected ray and the refracted ray is 90°, calculate \(\theta\), given that the refractive index of glass is 1.50.

Question 50:

• WAEC 2012

(a)


In the diagram illustrated, a body of mass m slides on an inclined plane. Show that the coefficient Mg of friction between the surfaces in contact is tan \(\theta\).
A spiral spring with a metal extends by 10.5 cm in air. When the metal is fully submerged in water, the spring extends by 6.8 cm. Calculate the relative density of the metal. (Assume Hooke's law is obeyed)