10 - 01 - 12Q.1

Find the following simultaneous equations.

i) 2x + y = 5 : 3x - y = 5

ii) x + y – 8 = x + 2y – 14 = 3x + y - 12 2 3 11

Q.2

i) The frequency of a source of sound is 100Hz. How many time does it vibrate in a minute ii) Define frequency

11 – 01 – 12Q.1 i) Solve: 2x – 3y =14; 5x + 2y =16

ii) x + y - x – y = 1 4 3

Q.2 i) Define reverberation

ii) How can it be reduced

12 -01 – 12

Q.1 i) 2x + 3y = - 4 ; x - 5y = 11

ii) 5y – 3x = 14 ; 3y – 2x = 1 iii) 2x – y – 3 = 0 ; 4x – y – 5 = 0

Q.2 Define : a) Longitudinal waves b) Transverse waves

2) Which range is known as audible range.

13 -01 -12 Q.1 Find the values of (x + y) and (x - y) from the examples given below without

solving for x and y

i) 5x + 7y =17 ; 7x + 5y = 19

ii) 7x -5y = -1 ; 5x -7y = - 11

Q.2 1. Define a) Sound b) Echo

2. Write long form of SONAR

GOKUL ACADEMY OF SCIENCE15, Near Gajanan High School, New Subhedar Lay-out, Nagpur-24

Ph.No.0712-2743707 & 6466067

Date :10-01-2012 Gokul Retrospection sheet 01

Std :IX-State

( G.R.S. -01)

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