Step 1: Understand the role of boilers in nuclear propulsion systems.
Nuclear propulsion systems rely on reactors to generate heat through nuclear fission, which is then used to produce steam for turbines. Boilers used in such systems must efficiently handle high pressures, temperatures, and specific requirements for nuclear safety.
Step 2: Analyze the options.
Water tube boiler (Option A):Although widely used in conventional steam generation, it is not suitable for nuclear propulsion systems because it does not meet the specific safety and operational requirements of nuclear reactors.
Cochran boiler (Option B): This is a fire-tube boiler used for small-scale applications. It cannot handle the high-pressure and high-temperature requirements of nuclear propulsion systems.
Double evaporation boiler (Option C): This boiler is used in specialized non-nuclear applications to improve thermal efficiency. However, it is not part of the standard nuclear propulsion system for ships.
Boiled water reactor boiler (Option D): This is integral to nuclear propulsion systems as it uses nuclear fission to generate steam directly, making it essential in such applications.
Step 3: Determine the correct answer.
Boilers not used in nuclear propulsion systems are: Water tube boiler (A), Cochran boiler (B), Double evaporation boiler (C). Conclusion: The boilers NOT used in nuclear propulsion systems for ships are Water tube boiler, Cochran boiler, and Double evaporation boiler.
A steel deck plate of a tanker is supported by two longitudinal stiffeners as shown in the figure. The width of the plate is \( a \) and its length is 5 times the width. Assume that the long edge is simply supported, and the short edge is free. The plate is loaded by a distributed pressure, \( p = p_0 \sin\left(\frac{\pi y}{a}\right) \), where \( p_0 \) is the pressure at \( y = a/2 \). The flexural rigidity of the plate is \( D \). The plate equation is given by 
Consider the matrices
\( M = \begin{pmatrix}
2 & 1 \\
0 & 2
\end{pmatrix} \)
\( N = \begin{pmatrix}
1 & 0 & 0 \\
1 & 2 & 0 \\
1 & 1 & 0
\end{pmatrix} \)
Which one of the following is true?
A ship with a standard right-handed coordinate system has positive \(x\), \(y\), and \(z\) axes respectively pointing towards bow, starboard, and down as shown in the figure. If the ship takes a starboard turn, then the drift angle, sway velocity, and the heel angle of the ship for a steady yaw rate respectively are: 
A ship of 3300 tonne displacement is undergoing an inclining experiment in seawater of density 1025 kg/m\(^3\). A mass of 6 tonne is displaced transversely by 12 m as shown in the figure. This results in a 0.12 m deflection of a 11 m long pendulum suspended from the centerline. The transverse metacenter of the ship is located at 7.25 m above the keel.
The distance of the center of gravity from the keel is ________ m (rounded off to two decimal places).
A multi-cell midship section of a ship with \( B = 40 \, {m} \) and \( D = 20 \, {m} \) is shown in the figure. The shear-flows are given as \( q_1 = q_2 = q_3 = 0.9376 \, {MN/m} \). The applied twisting moment on the midship section is __________ MN·m (rounded off to two decimal places).
Consider a weightless, frictionless piston with a 2 kg mass placed on it as shown in the figure. At equilibrium in position 1, the cylinder contains 0.1 kg of air. The piston cross-sectional area is 0.01 m2. The ambient pressure in the surroundings outside the piston-cylinder arrangement is 0 bar (absolute). When the mass above the piston is removed instantaneously, it moves up and hits the stop at position 2, which is 0.1 m above the initial position.
Assuming \( g = 9.81 \, {m/s}^2 \), the thermodynamic work done by the system during this process is ________ J (answer in integer).
Consider the psychrometric process denoted by the straight line from state 1 to 2 in the figure. The specific humidity, Dry Bulb Temperature (DBT), and Wet Bulb Temperature (WBT) at the two states are shown in the table. The latent heat of vaporization of water \( h_{fg} = 2440 \, {kJ/kg} \). If the flow rate of air is 1 kg/s, the rate of heat transfer from the air is_________kW (rounded off to two decimal places).
Water of density \( \rho = 1000 \, {kg/m}^3 \) flows with a velocity \( V = 50 \, {m/s} \) through a 180° curved tube of uniform cross-section as shown in the figure. If the flow rate is \( 0.06 \, {m}^3/{s} \), the magnitude of the reaction force \( F_x \) required to keep it stationary is ________ kN (rounded off to one decimal place).