51) 48, 45, 40, 33, 24, ...
(A) 13
(B) 11
(C) 8
(D) 3
52) Akbar sold his gun for Rs 900 which he bought for Rs 2500. What his % loss?
(A) 64%
(B) 32%
(C) 57%
(D) 72%
53) Ali sold his car for Rs. 43,000. He bought it for Rs. 50,000. What is his percentage loss?
(A) 14%
(B) 16%
(C) 17%
(D) 28%
54) Find the interest on Rs. 300 for 2 1/2 years at 4% per year?
What is the amount at the end of 2 1/2 years?
(A) Rs. 40, Rs. 300
(B) Rs. 10, Rs. 400
(C) Rs. 25, Rs. 280
(D) Rs. 30, Rs. 330
55) A hydrophone is:
(A) An instrument to detect sound under water
(B) A kind of brass musical instrument
(C) A machine reproducing in typed from what is spoken into it
(D) None of these
56) The voice of a mosquito is quite distinct from that of lion because
(A) The frequencies of two sounds differ widely
(B) The two sounds have different phases
(C) The two sounds travel with different speeds
(D) Of all the reasons stated above
57) If the intensity of one sound is 10 times the intensity of another, the two sounds differ by?
(A) 10 decibel
(B) 1 decibel
(C) 20 decibel
(D) 100 decibel
58) According to Laplace sound travels in air as a
(A) Transverse wave motion
(B) Longitudinal wave motion
(C) Transverse as well as Longitudinal wave motion
(D) None of these
59) Which of the following does not affect the reverberation time of a room?
(A) Area of the walls
(B) Volume
(C) Frequency
(D) Absorption co-efficient
60) No sound can be heard in
(A) Air
(B) Water
(C) Room temperature
(D) Vacuum