Mixed Deck — All IST Topics Flashcards

Which principle explains why a hydraulic press can lift a heavy object with a small force?

Answer: Pascal's Principle

Pascal's Principle states that a pressure change at any point in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. In a hydraulic press, a small force applied to a small piston creates pressure that is transmitted to a larger piston, resulting in a much larger force capable of lifting heavy objects.

What does 'GFCI' stand for and what does it protect against?

Answer: Ground Fault Circuit Interrupter — protects against ground fault shock

GFCI stands for Ground Fault Circuit Interrupter and protects people from electric shock caused by ground faults.

A Pareto chart is most useful for which of the following purposes?

Answer: Identifying the most significant causes contributing to a problem

A Pareto chart ranks causes by frequency or impact, helping teams focus on the 'vital few' causes that account for most problems.

How do you reverse the rotation of a three-phase induction motor?

Answer: Swap any two of the three line leads

Interchanging any two supply phases reverses the rotating magnetic field.

A turned part tapers from 2.000 in. to 1.500 in. in diameter over a length of 4 inches. What is the taper per inch?

Answer: 0.125 in.

The diameter changes by 0.500 in. over 4 in., so 0.500 / 4 = 0.125 in. per inch.

Which of the following describes the mechanical advantage of an inclined plane?

Answer: The length of the plane divided by the height of the plane

The mechanical advantage (MA) of an inclined plane is calculated by dividing the length of the inclined surface by its vertical height. This ratio indicates how much the input force is multiplied, making it easier to move an object vertically by pushing it along a longer, gentler slope. A higher MA means less effort is required.

What device is used to protect an electrical circuit from damage caused by excess current?

Answer: Fuse or circuit breaker

Fuses and circuit breakers protect circuits by interrupting the flow of current when it exceeds a safe level.

Which of the following is a characteristic of a regular tetrahedron?

Answer: Four triangular faces

A regular tetrahedron is a polyhedron composed of four equilateral triangular faces, with three meeting at each vertex. It is the simplest of all convex regular polyhedra and is also known as a 3-simplex. Its defining characteristic is having four identical triangular faces.

Which wire rope condition requires removing the rope from service?

Answer: Birdcaging or kinking

Birdcaging (strands spreading apart) and kinking are permanent structural damage that greatly reduce the rope's strength. Either one means the rope must be removed from service.

A machine uses 15 gallons of coolant per day. How many gallons are needed for a 5-day work week?

Answer: 75 gallons

Multiplying 15 gallons/day by 5 days equals 75 gallons.

What type of line in a technical drawing represents the visible outline or edge of an object?

Answer: Object line (visible line)

Object lines (visible lines) are solid, thick continuous lines that represent edges and outlines directly visible from the current viewing angle.

Which hydraulic component converts fluid energy into straight-line (linear) motion?

Answer: Hydraulic cylinder

A hydraulic cylinder is a linear actuator: fluid pressure pushes on its piston and extends or retracts the rod. A hydraulic motor produces rotary motion, and a pump produces flow.

Which shape will the net of a cube form when folded?

Answer: Cube

A net is a two-dimensional pattern that can be folded to form a three-dimensional shape. The net of a cube is specifically designed with six square faces arranged in a way that, when folded along its edges, it perfectly encloses a space to create a cube. This is the fundamental definition and purpose of a cube's net.

A 2,000 lb load is lifted with a two-leg bridle sling. Each leg is at 60° from horizontal. About how much tension is on each leg?

Answer: 1,155 lb

Each leg carries half the load (1,000 lb) times the sling angle factor. At 60°, that factor is 1/sin(60°) ≈ 1.155, so each leg carries about 1,155 lb. Leg tension rises as the angle gets flatter.

What safety precaution is most important before using a portable angle grinder?

Answer: Ensure the disc is the correct RPM rating for the grinder

The disc's maximum RPM rating must meet or exceed the grinder's speed to prevent the disc from disintegrating at high speed.

What is the correct procedure when using a file to smooth a metal surface?

Answer: Apply pressure only on the push (forward) stroke

Files are designed to cut on the forward (push) stroke only; dragging them back damages the teeth.

Six bolt holes are spaced equally around a bolt circle. What is the angle between the centers of adjacent holes?

Answer: 60°

A full circle is 360°, and 360 / 6 = 60°.

What is the purpose of a PLC (Programmable Logic Controller) in an industrial setting?

Answer: To automate and control industrial machinery and processes

PLCs are industrial computers used to automate machinery and processes based on programmed logic and sensor inputs.

Which three-dimensional shape will you get if you rotate a rectangle around one of its sides?

Answer: Cylinder

When a rectangle is rotated around one of its sides, that side becomes the axis of rotation. The opposite side sweeps out a circular path, forming the top and bottom circular bases of the resulting three-dimensional shape. The other two sides of the rectangle trace out the curved lateral surface, thus creating a cylinder.

Which OSHA standard requires employers to maintain records of work-related injuries and illnesses?

Answer: 29 CFR 1904

29 CFR 1904 is OSHA's recordkeeping standard that requires employers to record and report work-related injuries and illnesses.