Question 1
State the effect on the image in a pinhole camera when the length of the camera is reduced and the object distance is fixed
Answer
The image is reduced in size and more clear
Question 2
Define the term progressive waves.
Answer
Waves that move continuously away from the source
Question 3
Arrange the following electromagnetic waves in ascending order of frequency.
Infrared, x – rays, visible light, radiowaves
Answer
Radio waves, infrared, visible light, x – rays
Question 4
A radioactive substance has a mass of 0.2g and an activity of 1.0 x 103 disintegration per second at t = 0. What would be the activity of a sample of mass 0.6g of the same substance at the time t = 0
Answer
Question 5
A bar magnet was suspended freely above another bar magnet with marked poles as shown in figure 1.
State the poles at X an Y of the suspended magnet
Answer
X – South pole
Y – North pole
Y – North pole