BSEP ASVAB/ AFCT Mechanics Actual Exam Questions And Correct Detailed Answers.

When a load is hoisted by means of the tackle shown above, the part that remains stationary is the - correct answer Because the upper block is connected to an immovable hook, it must remain stationary The figure above shows a cam and a valve. For each cam revolution, the vertical valve rise equals distance - correct answer The distortion of the cam causes the valve to rise when contact is made. The amount of this distortion is the length Y. If all valves are closed at the start, in order to have air pressure from the tank move the pistons to the right, the valves to be opened are - correct answer To move the pistons to the right, valves 1, 3, and 4 must be open. Valve 4 permits the air to enter the system; valve 3 allows the air to hit the left side of the piston; and valve 1 is an exhaust channel for the air. Automatic operation of a sump pump is controlled by the - correct answer When the water level rises past the safe area, the float turns on the sump pump. When the level of water in the sump goes down, the float also goes down and will shut off the sump pump. The figure above shows a governor on a rotating shaft. As the shaft speeds up, the governor balls will move - correct answer The centrifugal force acts to pull the balls outward. Since the two balls are connected to a yolk around the center bar, this outward motion pulls the balls upward The figure above shows a crank and piston. The piston moves from mid-position to the extreme right if the crank makes - correct answer The piston is now in part of the compression stroke; 14 turn will move it to full compression; 12 more turn will move it to the end of the power stroke. Adding 14+12=34 turn. Referring to the figure above, which one of the following statements is true? - correct answer To tighten the bolt, turn it counterclockwise. To tighten the nut on the bolt the reverse is true—turn it clockwise. Which hydraulic press requires the LEAST force to lift the weight? - correct answer Pressure is defined as Force Area. For a given force, 20 lbs, the smaller the area, the greater the pressure produced. The smallest area is at position A, requiring the least force to lift the weight. The try-cocks of steam boilers are used to - correct answer The try-cocks show the level of the water inside the boiler. They use the principle that water seeks its own level in a system. In the case of the standard flanged pipe shown above, the maximum angle through which it would be necessary to rotate the pipe in order to line up the holes is - correct answer There are 8 holes in the circular cross-section of the flanged pipe. All circles have 360°. Thus, each hole is separated by 360°/8 or 45°. The force F needed to balance the lever shown above is, in pounds, most nearly - correct answer The sum of the moments must be zero. Summing around the fulcrum we have: (6 ft. × 5 lbs) + (3 ft. × 10 lbs) = 6 ft. × F Combining terms, we get: 60 (ft. - lbs) = 6 ft. × F Dividing both sides by 6: 10 lbs = F If the ball and spring mechanism is balanced in the position shown above, the ball will move upward if the - correct answer The ball will move up if the arm holding it is pulled up. This will happen when the nut is tightened. In the structural steel splice above, the different types of rivets are shown by different symbols. The number of different types of rivets is - correct answer There are only 4 different types of symbols The above illustration shows a worm and gear. If the worm rotates slowly on its shaft, the gear will - correct answer For every full rotation of the worm shaft, the gear will turn only 22°. A very light cut (trace) is being measured as a check before cutting the thread on the lathe. The number of threads per inch shown above is - correct answer The problem here is that only part of a ruler is shown. Count 4 units on the 8th scale. This corresponds to 612 threads on the length to be threaded. Doubling the 612 (in 12 inch) we get 13 threads in 1 inch. In the above figure, if pulley A is the driver and turns in direction 1, which pulley turns fastest? - correct answer Pulley A has the smallest circumference and therefore turns the fastest. In the diagram above, pulley A drives a system of pulleys. Pulleys B and C are keyed to the same shaft. Use the following diameters in your computations: A = 1 inch; B = 2 inches; C = 12 inch; and D = 4 inches. When pulley A runs at an rpm of 2,000, pulley D will make - correct answer The larger the pulley, the more distance it must cover, and therefore, the smaller the rpm. If A turns at 2,000 rpm, B (twice as large) turns at 1,000 rpm; C is attached to B and