General instructions
1) This question paper comprises of two sections (Section : Phye
Science, Section of Natural Science), You have to attempt
sections
(0) All questions are compulsory
ii) Question numbers 1 and 2 are one mark questions. These are to be
answered in one word or one sentence.
lv)Question numbers 3 to 6 are two marks questions. These are to be
answered in about 30 words each.
v) Question numbers 7 to 11are three marks questions. These are to be
answered in about 50 words each,
vi)Question numbers 12 to 14 are five marks questions. These are to be
answered in about 70 words each,
SECTION - A PHYSICAL SCIENCE
Marks: 40
1. Answer the following questions in one or two sentences:
2x1=2
1. What is the range of audible vibrations for the normal human ear?
2. Define force and write the SI unit of force.
II. Answer the following questions in short form:
4x2=8
3. Does pure water conduct electricity? If not, what can we do to make it
conductivity?
4. A pendulum oscillates 48 times in 3 seconds. Find the time period and
frequency?
5. What is the difference between noise and music?
Answers
Answer:
1. 20 decibel is the range of audible vibration for normal human ear.
2. an object of constant mass accelerates in proportion to the force applied.
SI Unit
is
Newton.
II. Answer
3. Pure water cannot conduct electricity, because it does not contain ions. We can dilute pure water with acid or a base or a salt, as they produce ions due to the dilution.Only water conduct electricity because it contain minerals in it.
4. The frequency of oscillations is the number of oscillations of a vibrating object per second. Therefore frequency = 48 vibrations /3 seconds= 16 Hertz.
Time period
is the time required to complete one oscillation. Frequency is the inverse of the time period. Therefore time period
= 1/16 = 0.06
5. Music is a sound which produces a pleasing sensation while noise is an unwanted and unpleasant sound. Music is produced by musical instruments like piano, guitar, flute, etc.
Noise is produced by horns of vehicles, crackers, machines, etc and hence it leads to noise pollution