  # ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2020

Instructions

For the following questions answer them individually

Question 11

# The operating temperatures of a single stage Vapour Absorption Refrigeration System (VARS) are : Generator $$90^\circ C$$, condenser and absorber $$40^\circ C$$, evaporator $$0^\circ C$$. If the pump work is negligible, find the ideal COP of this VARS Question 12

# One of the Eigen vectors of the matrix $$\begin{bmatrix}-5 & 2 \\-9 & 6 \end{bmatrix}$$ Question 13

# A disc of radius R rotates at an angular velocity $$Ω$$ inside a disc shaped container filled with oil of viscosity $$\mu$$, as shown in figure. Assuming a linear velocity profile and neglecting shear stress on the outer disc edges, the formula for viscous torque on the disc is  Question 14

# A dam has a parabolic shape $$\frac{z}{z_0} = \left( \frac {x}{x_0}\right)^2$$ as in shown in figure. with $$x_0 = 3 m$$ and $$z_0 = 7 m$$ The fluid is water (specific weight = 9810 N/m$$^3$$) and atmospheric pressure may be omitted. Compute the horizontal force $$F_H$$ and its line of action from surface of water ‘d’. Assume width of dam is 15 m.  Question 15

# Calculate the forces in the members CG and CF for the truss shown.  Question 16

# Which of the following statement regarding centrifugal compressor is true? Question 17

# Which one of the following statements is true? Question 18

# Three cards were drawn from a pack of 52 cards. The probability that they are a king, a queen and a jack is Question 19

# General solution to the equation $$(x^3 + 3xy^2)dx + (3x^2y + y^3)dy = 0$$ is (c is a constant) Question 20

# Let $$f(t) = \sin^2 t,$$ find the Laplace transform of f(t) OR