1. Increase in the frequency of_____________ with rumbling sounds; occurrence of volcanic tremors; *
2. Increased ______________activity; change in color of steam emission from white to gray *
3. _______________due to presence of magma at or near the crater; *
4. Ground ______________(inflation), ground tilt and ground________________ due to magma intrusion;
5. Localized ________________, __________________ and landslides from summit area which are not attributed to heavy rains; *
6. Noticeable increase in the extent of ______________of vegetation around the volcano’supper slopes; *
7. Increase in the ______________ of hot springs, wells and crater lake near the volcano; of springs, *
8. Noticeable variation in the ___________________, crater lakes within the vicinity of the volcano; *
1 point
9. ________________of springs/wells around the volcano; *
10. _________________exhibit unusual behaviors as they sense the volcano’s restiveness; and *
11. Development of _________ areas and/or __________ of old ones’ appearance of ___________.
Answers
Answer:
Exercise Questions
1. Choose the correct answer.
Sound can travel through
(a) gases only
(b) solids only
(c) liquids only
(d) solids, liquids and gases
Soln:
Answer is (d) solids, liquids and gases
Explanation:
For the sound to travel, it requires a medium. Solids, liquids and gases provide a medium through which sound can travel.
2. Voice of which of the following is likely to have a minimum frequency?
(a) Baby girl
(b) Baby boy
(c) A man
(d) A woman
Soln:
Answer is (c) A man
Explanation:
When compared to the voices of a baby boy, baby girl, and woman, the voice of a man has a lower pitch. As the pitch of a man is low, which is proportional to the frequency of a sound, the man’s voice is of minimum frequency as compared with others.
. Fill in the blanks with suitable words.
(a) Time taken by an object to complete one oscillation is called __________.
(b) Loudness is determined by the __________ of vibration.
(c) The unit of frequency is __________
(d) Unwanted sound is called __________ .
(e) The shrillness of a sound is determined by the __________ of vibration.
Soln:
(a) Time taken by an object to complete one oscillation is called time period.
(b) Loudness is determined by the amplitude of vibration.
(c) The unit of frequency is Hertz.
(d) Unwanted sound is called Noise.
(e) The shrillness of a sound is determined by the frequency of vibration.