Q no 21. Intensity of sound having sound level of 80dB is?
10^-1 W per m sq
10^-2 W per m sq
10^-3 W per m sq
10^-4;W per m sq

Q no 22. A sound having intensity 3*10^-6 W per m sq. Find its intensity level in dB?
40.8 dB
64.8 dB
None

Q no 23. When water waves traveles from low depth area to more deep water then frequency , wavelength and speed will be?
Same, decrease, increase
Same, increase,increase
Increase, decrease,increase
None

Q no 24. Speed of transverse waves will be greater in?
Solids
Liquids
Gases
None

Q no 25. In torsional oscillator the frequency of oscillator is related to Torsional constant as?
Directly proportional
Inversely proportional
Both

Q no 26. If spring constant of mass spring system is doubled then time period will?
Increase 2 times
Will decrease by 0.71 times
Will increase √2 times
Remains same

Q no 27. At what value of A(amplitude) the velocity of body in SHM will be half of the maximum velocity?
√3/2 A
√5/4A
√5/2 A
None of these

Q no 28. Length of seconds pendulum will be on earth approx?
1.5 m
1.25 m
1 m
None

Q no 29. b<2√Km is the condition of ( where b is damping constant)?
Over Damping
Under damping
Critical damping
None

Q no 30. fe=( v+Uo/V-Uo)f this relation indicates the change in freqency when?
Observer is moving towards source
Observer is moving away from source
Both observer and source are moving towards each other
Both are moving away

Q no 31. Which harmonics are possible in one end closed pipe?
Even harmonics
Only odd harmonics are possible
All are possible
None

Q no 32. The speed of waves will be on doubling the tension and halving the mass per unit length?
Remains same
Increase √2 times
Increase 2 times
Decrease √2 times

Q no 33. Which pair have same relations for wavelength and frequency(for string and pipe)?
One end closed, both ends open
One ends fixed and both ends open
Both ends open and both ends fixed
None of these

Q no 35. Number of nodes and antinodes in one end open pipe for 2nd mode will be?
2 node 3 antinode
2 N 2 A
3 N 2 A
None

Q no 36. When a waves move from high density to low density?
Half wave will be transmitted and half will be reflected with same phase
Half wave will be transmitted and half will be reflected with opposite phase

Q no 37. The temperature at which speed of sound in air is two times of its speed at 0C?
1092K
819C
819K
546C
both a and b

Q no 38. The frequency of physical pendulum is related to restoring torque?
Directly to √torque
Inversely to √torque
No effect f will be remains same
None

Q no 39. M1 Peshawar to Islamabad motorway have a length of?
892km
155km
280km
none of these

q no 40. TARBEELA POWER HOUSE have a capacity of power generation approx.?
1320MW
1600MW
3478MW
NONE

Q NO 41. which area have more percent of forest area?
punjab
sindh
AJK
BALOCHISTAN

Q NO 42. KPK have forest area about?
10%
20%
30%
40%

Q NO 43. PAKISTAN have forest area of about?
2%
3%
4.8%
6%

Q no 44. Which country have most forest area in the world?
USA
CANADA
RUSSIA
CHINA