### Physics Past Questions

16

The equation of a wave traveling along the positive x-direction is given by;
y = 0.25 x 10$$^{-3}$$ sin (500t - 0.025x).
Determine the angular frequency of the wave motion.

• A. 0.25 x 10-3rad s-1
• B. 0.25 x 10-1rad s-1
• C. 5.00 x 102rad s-1
• D. 2.50 x 103rad s-1
JAMB 1999
17
If a sound wave goes from a cold air region to a hot air region, its wavelength will
• A. increase
• B. decrease
• C. decrease then increase
• D. remain constant
JAMB 1999
18
The lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40hz and 180Hz?
• A. 4
• B. 3
• C. 2
• D. 1
JAMB 1999
19
A man stands 4m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and his new image is
• A. 3m
• B. 5m
• C. 6m
• D. 10m
JAMB 1999
20
The inside portion of part of a hollow metal sphere of diameter 20cm is polished. The portion will therefore form a
• A. concave mirror of focal length 5cm
• B. concave mirror of focal length 10cm
• C. convex mirror of focal length 5cm
• D. convex mirror of focal length 20cm
JAMB 1999