ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2020

0.94

1.4

0.84

2.4

$$\begin{bmatrix}-1 \\1\end{bmatrix}$$

$$\begin{bmatrix}-2 \\9\end{bmatrix}$$

$$\begin{bmatrix}2 \\-1\end{bmatrix}$$

$$\begin{bmatrix}1 \\1\end{bmatrix}$$

$$\frac{\pi \mu Ω R^2}{h}$$

$$\pi \mu Ω h R^3$$

$$\frac{\pi \mu Ω R^5}{h^2}$$

$$\frac{\pi \mu Ω R^4}{h}$$

$$F_H = 3605 kN, d = 1.16 m$$

$$F_H = 3605 kN, d = 4.66 m$$

$$F_H = 4300 kN, d = 4.66 m$$

$$F_H = 4300 kN, d = 1.16 m$$

$$F_{CG} = \sqrt 5 kN, F_{CF} = 1 kN$$

$$F_{CG} = \sqrt 3 kN, F_{CF} = 2 kN$$

$$F_{CG} = 2 kN, F_{CF} = \sqrt 1 kN$$

$$F_{CG} = \sqrt 5 kN, F_{CF} = 2 kN$$

Conversion of dynamic pressure into static pressure takes place in the volute casing due to its convergent shape

In multi stage centrifugal compressor, the width of the blades reduces progressively in the direction of flow

In multi stage centrifugal compressor, the width of the blades increases progressively in the direction of flow

Multi staging in centrifugal compressors is commonly used for high refrigerant capacity applications

Compared to reciprocating compressor, the performance of centrifugal compressor is less sensitive to speed

Surging in centrifugal compressor takes place as evaporator pressure increases and condenser pressure decreases

Surging in centrifugal compressor takes place as evaporator pressure decreases and condenser pressure increases

For a given flow rate, frictional losses decrease as the number of blades increases

$$\frac {16}{5525}$$

$$\frac {64}{2197}$$

$$\frac {3}{13}$$

$$\frac {8}{16575}$$

$$\frac {1}{4}(x^4 + 6x^2y^2 + y^4) = c$$

$$\frac {1}{5}(8x^4 + 6x^3 y + y^3) = c$$

$$\frac {1}{12}(x^3 + 6xy^2 + y^4) = c$$

$$(x^2 + y^2) = c$$

$$\frac {2}{s^2 + 4}$$

$$\frac {2}{s(s^2 + 4)}$$

$$\frac {2s}{s^2 + 4}$$

$$\frac {2}{s(s^2 - 4)}$$