Physics 2013 Waec Past Questions and Answers

Question 21 :

• WAEC 2013

When salt is dissolved in water, the freezing point of the water

A. Increases
B. Decreases
C. Remains the same
D. Increases and later decrease

Question 22 :

• WAEC 2013

The equation of a certain progressive transverse wave is y = 2 sin 2 \(\pi ( \frac{t}{0.01} - \frac{x}{30})\), where x and y are in cm and t in seconds. Calculate the period of the wave.

A. 0.001s
B. 0.010s
C. 10.000s
D. 100.000s

Question 23 :

• WAEC 2013

At which position should an object be placed in front of a concave mirror in order to obtain an image which is of the same size as the object?

A. At the centre of curvature
B. At the principal focus
C. Between the pole and principal focus
D. Between the centre of curvature and principal focus

Question 24 :

• WAEC 2013

Images formed by a convex mirror are always

A. Magnified
B. Behind the mirror
C. Real
D. Inverted

Question 25 :

• WAEC 2013

The refractive index of a material is 1.5. Calculate the critical angle at the glass-air interface

A. 19^o
B. 21^o
C. 39^o
D. 42^o