Question

:Just as we need Oxygen to breathe a vehicle needs Oxygen for the combustion process for producing energy from fuels like Gasoline, Diesel etc. (Not for electric/Solar vehicles)The figure shows two types of Air fiters of a Volvo truck and Car. An air filter is designed to protect the engine of a vehicle from harmful particles and pollutants. It ensures that large debris items like leaves, bugs, dust and other matter don’t get into your vehicle engine’s delicate system. It allows only pure air intake. Regular maintenance and replacement of Air filters increase the life time of the engine and vehicle.An air filter is usually made of a spun fiberglass material or pleated paper or cloth enclosed in cardboard frame. Some durable filters have perforated copper plates enveloping the filter system from outside as shown in figures. Though there are many different types by material, shape, cost etc. the example given in the figures are of cylindrical and perforated copper plate type filters.

The air filters in fig. (i) and (ii) have their heights in the ratio 1:2.The taller one has a height of 32 cm. The outer and inner radii are equal for both the filters. The measures are 7cm and 5cm respectively.

Q1. What is the ratio of curved surface area of the larger filter to that of the smaller filter?
A) 1:2
(B) 2:1
(C) 1:4
(D) 4:1
2.What is the outer curved surface area of the small filter?
A) 212sq.cm
(B)704sq.cm
(C) 256sq.cm
D) 240 sq.cm
3.If the perforations of the copper plate (circular holes) cover 72% of the curved surface area of the filter, then what will be the area of actual copper used in the outer protective layer of the Larger filter
(A) 1609.14 sq.cm
(B) 1158.58 sq.cm
(C) 394.24 sq.cm
(D) 1013 . 76 sq.cm
4.The inner volume (free space) of the smaller filter approximately equal to

420 Cubic cm
1600 Cubic cm
1000 Cubic cm
800 Cubic cm

Answer 1

Answer:

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