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REVISION QUESTIONS , CHAPTER 1, CLASS 9, MEASUREMENT



CLASS 9, PHYSICS
FULL MARKS : 20
All Questions are compulsory. 
Q1. Define : a) measurement,  b) unit of a physical quantity.  2
Q2. State the SI unit of a) Luminous intensity,  b) solid angle. 2
Q3. Fill in the blanks a) 1 metre= _____________ micrometre.
                                      b) 1 Kg= _____________ metric tonne. 2
Q4. Compare the time period of two pendulum of length 2 m and 18 m. ( g=9.8 metre per square second) 2
Q5. State how does the time period of a simple pendulum depends on a) acceleration due to gravity, 
        b) length of pendulum and   c) amplitude of oscillation. 3
Q6. Define a) amplitude of a simple pendulum, b) frequency  of a simple pendulum  and c) seconds pendulum. 3
Q7. What are the three requirements  for selecting a good unit of a physical quantity. 3
Q8 Write the derived unit of FORCE ( in terms of symbols of basic units) in a) MKS b) CGS and c) FPS system of unit. 3
ANSWERS:
A1. a) Measurement is the process of comparing the value of a physical quantity with a chosen standard value of same kind. B) The standard quantity selected to measure a physical quantity is called  a unit.
A2a) candelabra   b) steradian
A3 a) 10^6 ( ten to the power of six) b) 10^-3
A4. T1/T2=\ /~~l1/l2 =\/~2/18=\/~~1/9=1/3= 1:3
A5. Time period is inversely proportional to the square root of acceleration due to gravity. 
Time period is directly proportional to the square root of the length of a pendulum.
Time period does not depend on the amplitude.

Answers from 6 to 8 for your practise (Please do it yourself ) If you want any answers please do write in comment section.
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