1. GOKUL ACADEMY OF SCIENCE
15, 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)
10 - 01 - 12
Q.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 – 12
Q.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
Go Cool For Exam
.