Advertisements
Advertisements
Question
Differentiate between the following:
Radio waves and light waves.
Advertisements
Solution
| Radio waves | Light waves |
| 1. Radio waves are not visible to hum an eye. | 1. Light waves are visible to human eye. |
| 2. These waves range from 105 to 10-3 meters. | 2. These waves range from 10-6 to 10-7 meters. |
| 3. Frequency of radio waves is below 107 Hz. | 3. Frequency of light waves lie in the range 1014 to 1013 Hz. |
| 4. Its sources are TV and radio transmitters. | 4. Its sources are sunlight, white hot bodies. |
APPEARS IN
RELATED QUESTIONS
Which characteristic of sound makes it possible to recognize a person by his voice without seeing him?
In fig. , P, Q, R and S represent test tubes each of height 20 cm which are filled with water upto heights of 10 cm, 14 cm, 16 cm and 18 cm respectively. If a vibrating tuning fork is placed over the mouth of test tube Q, a loud sound is heard.
(i) Describe the observations with the tubes P, R and S.
(ii) Give the reason for your observation in each case.
(iii) State the principle illustrated by the above experiment.
In fig. shows two tuning forks P and Q of the same frequency mounted on separate sound boxes with their open ends facing each other. The fork A is set into vibration. (i) Describe your observation. (ii) State the principle illustrated by this experiment.
In Fig. A, B, C and D are four pendulums suspended from the same elastic string XY. The lengths of pendulum A and D are equal, while the length of pendulum B is shorter and of the pendulum C is longer. Pendulum A is set into vibrations.
- What is your observation about the vibrations of pendulum D?
- Give reason for your observation in part (a).
- What type of vibrations take place in pendulums Band C?
- Give reason for the answer in part (c).
Explain a tuning fork (vibrating) is held close to ear. One hears a faint sound. The same vibrating tuning fork is placed on table, such that its handle is in contact with table, one hears a loud sound.
What do you understand by forced vibrations?
What do you understand by free vibrations of a body? Draw a displacement-time graph to represent them. Given one example.
When the stem of vibrating tuning fork is pressed on a table, the tabletop starts vibrating. These vibrations are definitely an example of ______.
