Question: As compared to a single free face, if a charge of explosive is placed equidistant from two faces, then the yield___________________?

• 1. remains same
• 2. decreases
• 3. increases by 2.25 times
• 4. increases by 3.5 times

Question: In “full face” method of constructing tunnels, the first operation relates to______________?

• 1. removal of bottom portion
• 2. excavation of one drift in the centre
• 3. removal of top portion
• 4. excavation being done along the periphery

Question: The ratio of average velocity to maximum velocity for steady laminar flow in circular pipes is_______________?

• 1. 1/2
• 2. 2/3
• 3. 3/2
• 4. 2

Question: For laminar flow in a pipe of circular cross-section, the Darcy’s friction factor f is________________?

• 1. directly proportional to Reynolds number and independent of pipe wall roughness
• 2. directly proportional to pipe wall roughness and independent of Reynolds number
• 3. inversely proportional to Reynolds number and indpendent of pipe wall roughness
• 4. inversely proportional to Reynolds number and directly proportional to pipe wall roughness

Question: For hydro-dynamically smooth boundary, the friction coefficient for turbulent flow is_______________?

• 1. constant
• 2. dependent only on Reynolds number
• 3. a function of Reynolds number and relative roughness
• 4. dependent on relative roughness only

Question: With the same cross-sectional area and immersed in same turbulent flow, the largest total drag will be on__________________?

• 1. a circular disc of plate held normal to flow
• 2. a sphere
• 3. a cylinder
• 4. a streamlined body

Question: The distance y from pipe boundary, at which the point velocity is equal to average velocity for turbulent flow, is________________?

• 1. 0.223 R
• 2. 0.423 R
• 3. 0.577 R
• 4. 0.707 R

Question: In case of an airfoil, the separation of flow occurs________________?

• 1. at the extreme rear of body
• 2. at the extreme front of body
• 3. midway between rear and front of body
• 4. any where between rear and front of body depending upon Reynolds number

Question: The depth ‘d’ below the free surface at which the point velocity is equal to the average velocity of flow for a uniform laminar flow with a free surface, will be_________________?

• 1. 0.423 D
• 2. 0.577 D
• 3. 0.223 D
• 4. 0.707 D

Question: If x is the distance from leading edge, then the boundary layer thickness in laminar flow varies as________________?

• 1. x
• 2. x
• 3. x
• 4. x/7