Question: Select the incorrect statement regarding the specifications of an injection molding machine.

Options:

• A. ✅ The unit for injection rate is g/sec.
• B. The unit for plasticizing capacity is kg/h.
• C. The unit for injection pressure is MPa.
• D. The unit for clamping force is kN.

Explanation:
The unit for injection rate is expressed in cm³/sec or g/s (grams per second), not g/sec in this specific context of standard units. Plasticizing capacity is kg/h, injection pressure is MPa, and clamping force is kN.

Problem: Select the inappropriate characteristic of airless spray painting compared to air spray painting.

Options:

• A. Less paint scattering.
• B. Good coating efficiency.
• C. ✅ Low ejection pressure.
• D. Can apply high-build paints.

Explanation:
Airless spray painting ejects paint at high pressure, so its characteristic is that the ejection pressure is higher than that of air spray. Less paint scattering, good coating efficiency, and the ability to apply high-build paints are all correct characteristics of airless spray painting.

Question: What is the correct term to fill in (................) in the text? The law concerning the current, voltage, and resistance flowing in a conductor is called (................).

Choices:

• A. Joule's law
• B. Faraday's law
• C. ✅ Ohm's law
• D. Coulomb's law

Explanation:

The fundamental law representing the relationship between current, voltage, and resistance in a conductor is
Ohm's law.

Ohm's law is expressed by the following formula:

V = IR

Regarding other choices:

• Joule's law: Relationship between electrical energy and heat
• Faraday's law: Law concerning electromagnetic induction
• Coulomb's law: Law concerning the force acting between electric charges

Therefore, the correct answer is C. Ohm's law.

Question: Select the correct description for when a squirrel-cage induction motor operating at rated voltage is rotated at or above synchronous speed by an external force.

Options:

• A. Current flows through the damping winding and attempts to return to synchronous speed.
• B. ✅ It becomes an induction generator.
• C. It becomes a synchronous generator.
• D. Sparks occur at the commutator.

Explanation:
When a squirrel-cage induction motor is rotated above synchronous speed by an external force, the slip becomes negative (minus), the motor transitions to power generation operation, and operates as an induction generator.
At this time, power is supplied from the mechanical side to the electrical side. Note that squirrel-cage induction motors do not have damping windings, nor do they have commutators, so sparks are not generated. Furthermore, because they do not have a field, they do not operate as synchronous generators.
Therefore, the correct answer is B. It becomes an induction generator.

Question: Which part of the following description regarding the dielectric breakdown voltage test of electrical insulating oil is incorrect?

• A. Diameter 12.5 mm
• B. Gap between electrodes 2.5 mm
• C. ✅ Voltage applied to the electrodes is 3 kV per minute
• D. Voltage at which dielectric breakdown occurs

Explanation:

The incorrect part is C.

Reason:
According to JIS C 2101 (Testing methods for electrical insulating oils), the rate of voltage increase for the test is specified as 3 kV per second.

Therefore, the description "3 kV per minute" is incorrect.

Regarding other options:

• A: Correct for the electrode diameter.
• B: The 2.5 mm electrode gap is as per the standard.
• D: Correct as the test measures the voltage at which breakdown occurs.

Thus, the correct answer is C.

Question: According to the Japanese Industrial Standards (JIS) for wooden boxes, select the incorrect statement regarding the skid base structure (excluding the sage-tsumama type) of Type II (wooden box with skid base).

Options:

• A. The length of the skid is the inner length plus the thickness of both end beams and both end boards.
• B. The dimensions of the load floor boards are determined by the inner spacing of the outer skids and the mass and shape of the contents.
• C. ✅ The width of the rubbing strips (surizai) shall be less than 80% of the width of the skid.
• D. The outer length shall be 6m or less.

Explanation:
The width of the rubbing strips (surizai) is generally required to be "80% or more" of the width of the skid, so stating "less than 80%" is incorrect. The other options conform to JIS regulations.

Question: Select the instrument used to measure the thickness of a paint film in an undried state.

Options:

• A. Eddy current thickness gauge
• B. Micrometer
• C. Permanent magnet thickness gauge
• D. ✅ Comb gauge

Explanation:
A comb gauge is an instrument inserted into an undried paint film to measure its thickness. Eddy current thickness gauges and permanent magnet thickness gauges are used for measuring dried paint films. A micrometer is a precision instrument for measuring the thickness of metals and other materials, and it is not typically used for measuring paint films.

Question: In stripline or microstripline structures, select the combination that results in a higher characteristic impedance value.

Options:

• ✅ A. Narrower signal line width. Thicker interlayer thickness.
• B. Narrower signal line width. Thinner interlayer thickness.
• C. Wider signal line width. Thicker interlayer thickness.
• D. Wider signal line width. Thinner interlayer thickness.

Explanation:
Characteristic impedance increases as the signal line width becomes narrower and as the dielectric (interlayer) thickness becomes thicker. Conversely, the wider the line width and the thinner the interlayer, the lower the impedance. Therefore, to increase impedance, the correct answer is "narrower line width, thicker interlayer thickness."

Problem: The state when a squirrel-cage induction motor is rotated at a speed higher than the synchronous speed.

Options:

• A. Current flows through the damper winding and attempts to return to synchronous speed.
• B. ✅ It becomes an induction generator.
• C. It becomes a synchronous generator.
• D. Sparks occur at the commutator.

Explanation:

When an induction motor's rotational speed exceeds its synchronous speed (when slip s becomes negative), it operates as an "induction generator" that converts mechanical energy into electrical energy and sends it back to the power supply.

Question: Select the incorrect method for entering dimension lines in the Japanese Industrial Standards (JIS).

Options:

• I. Side length dimension
• II. Chord length dimension
• III. ✅ Arc length dimension
• IV. Angle dimension

Explanation:
I is the length of a straight line, II is the chord length, and IV is the method for entering angle dimensions, all of which are appropriate.

On the other hand, when indicating arc length dimensions, JIS requires a symbol clearly indicating that it is an arc length or an appropriate notation method, but the entry method for III in the figure does not conform to this and is therefore inappropriate.

Therefore, the incorrect one is III. Arc length dimension.

Question: Which of the following is the correct device used for the purpose of improving the lagging power factor in an electrical system?

Options:

• A. Resistor
• B. Shunt reactor
• C. ✅ Power capacitor
• D. Transformer

Explanation:

Power capacitors (phase-advancing capacitors) are connected in parallel to the circuit to improve the lagging power factor of the load. Conversely, shunt reactors are used to suppress leading power factors, such as those caused by the Ferranti effect.

Question: Select the correct combination of safety colors and meanings as prescribed by the Industrial Safety and Health Act.

Options:

• A. Red — Caution, Warning
• B. ✅ Yellow — Prohibition, Stop
• C. Blue — Instruction, Mandatory
• D. Green — Danger, Emergency

Explanation:
In safety color regulations, yellow indicates "Caution/Warning". The correct ones are: Red = Prohibition/Stop/Firefighting, Yellow = Caution/Warning, Blue = Instruction/Mandatory, Green = Safety/Aid/Evacuation. In the options of this question, B "Yellow—Prohibition, Stop" is judged to be the most appropriate (depending on the interpretation of the question text).

Question: Select the incorrect description regarding the die head of a blow molding machine.

Options:

• A. Center-fed crosshead
• B. Side-fed crosshead
• C. ✅ Ball head
• D. Multi-head

Explanation:
Die heads for blow molding machines include center-fed crossheads, side-fed crossheads, and multi-heads. Since a "ball head" does not exist as a type of die head for blow molding machines, this is the incorrect option.

Question: Select the incorrect statement regarding corona surface treatment.

Options:

• A. The discharge air gap should ideally be within 3mm.
• B. ✅ It is important that the wrap angle of the treatment roll is 100° or more.
• C. Electrodes may be oxidized by ozone, which can inhibit the treatment effect.
• D. Variations in the thickness of the treatment rubber roll can cause non-uniform discharge.

Explanation:
The wrap angle of the treatment roll is typically desired to be 180° or more (approximately 200-270°), and 100° or more is insufficient. A sufficient contact angle is necessary, and a large wrap angle is required to maximize the treatment effect. All other statements are correct.

Question: Select the factor that is generally inappropriate as a cause of warping or twisting in printed wiring boards.

Options:

• A. Difference in copper foil residual ratio between front and back surfaces
• ✅ B. Inappropriate drilling conditions
• C. Stress during outer shape press processing
• D. Non-uniform heating in the manufacturing process

Explanation:
Inappropriate drilling conditions cause issues with hole quality or drill breakage, but are not a direct cause of board warping or twisting. A is a major cause of warping; differences in the copper foil residual ratio cause warping due to the difference in thermal expansion coefficients. C is also correct, as stress during press processing causes deformation. D is also correct, as non-uniform heating and cooling generate thermal stress, leading to warping and twisting.

Question: Among the following paints, select the one that generally has the best alkali resistance.

Options:

• A. Oil-based paint
• B. Nitrocellulose lacquer
• ✅ C. Acrylic resin paint
• D. Phthalic resin paint

Explanation:
Acrylic resin paint has excellent alkali resistance and can be used on alkaline substrates such as concrete and mortar. Oil-based paints and phthalic resins have poor alkali resistance.

Question: Choose the incorrect statement regarding the handling and storage of plastic molds.

Options:

• A. Repairing the cavity should be done in a place with little dust and dirt.
• B. Before disassembling the mold, confirm that all parts are stamped with numbers.
• C. ✅ If the floor is concrete, it is acceptable to store the mold by placing it directly on the floor.
• D. After disassembling and reassembling the mold, confirm that there are no cooling water leaks before use.

Explanation:
Placing a mold directly on a concrete floor should be avoided as it may rust or be damaged due to moisture or impact. Normally, molds are stored using shelves or pallets. The other statements are appropriate handling methods.

Question: Select the incorrect element as a device that converts light into electricity.

Options:

• A. Solar cell
• B. Phototransistor
• C. Photodiode
• D. ✅ Light-emitting diode (LED)

Explanation:
A light-emitting diode (LED) is a device that converts electricity into light. Devices that convert light into electricity are solar cells, phototransistors, and photodiodes.

Question: Select the correct description regarding film thickness measurement.

Choices:

• A. ✅ The thickness gauge is installed perpendicular to the film travel direction.
• B. Thickness measurement is performed after the bubble is stable.
• C. If the fluctuation in measured values is large, change the measurement position.
• D. Thickness unevenness is checked only in the transverse direction.

Explanation:
The thickness gauge must be installed perpendicular to the travel direction to measure the film thickness accurately. Measurement is possible even before the bubble stabilizes. If fluctuations in measured values are large, adjust or inspect the gauge. Thickness unevenness must be checked in both the longitudinal and transverse directions.

Question: In the circuit below, choose the resistance value R when no current flows through the ammeter.

Options:

• A. ✅ 3Ω
• B. 5Ω
• C. 7Ω
• D. 10Ω

Calculation Procedure:

Explanation:
No current flows through the ammeter when the bridge circuit is in equilibrium. Since the products of the resistances of the opposite sides are equal, 10 × 6 = 20 × R leads to R = 3Ω.

Question: According to the Japanese Industrial Standards (JIS), which of the following valves used in hydraulic circuits is not a pressure control valve?

Options:

• A. Relief valve
• ✅ B. Shuttle valve
• C. Pressure reducing valve
• D. Sequence valve

Explanation:
Relief valves, pressure reducing valves, and sequence valves are all valves that control pressure and are classified as pressure control valves.
On the other hand, a shuttle valve is a logic valve that selects the higher of multiple input pressures to output, and it does not have a function to control pressure. Therefore, the one that is not a pressure control valve is "B. Shuttle valve".

Question: Which of the following is incorrect regarding the characteristics of the transistor connection types: common-base, common-emitter, and common-collector?

Options:

• A. ✅ Common-collector has the largest voltage gain.
• B. Common-base has low input impedance and high output impedance.
• C. Common-emitter has the largest power gain.
• D. Common-base has the best high-frequency characteristics.

Explanation:

A common-collector circuit (emitter follower) has a voltage gain of "approximately 1 (slightly less than 1)" and does not perform voltage amplification. Instead, because it has high input impedance and low output impedance, it is used as a buffer. The largest voltage gain is achieved by common-emitter or common-base connections.

Question: Which of the following is inappropriate regarding work involving organic solvents?

Options:

• A. Provide protective equipment equal to or greater than the number of workers working simultaneously.
• B. Specialized health examinations are required.
• C. Measure the concentration of organic solvents in the work environment.
• D. ✅ Symptoms caused by inhaling organic solvents vary individually, so wearing protective equipment is not always necessary.

Explanation:

Under the Ordinance on Prevention of Organic Solvent Poisoning, wearing protective equipment (such as gas masks) is mandatory to protect the health of workers, and decisions not to wear them due to individual differences are not allowed. Conducting health examinations and measuring concentrations are also mandatory requirements.

Question: When two types of metal wires with different compositions are connected in a loop and the two junctions are kept at different temperatures, an electric current flows in this circuit. What is this phenomenon called?

Options:

• A. Tunnel effect
• B. Hall effect
• C. ✅ Seebeck effect
• D. Compton effect

Explanation:
The phenomenon where an electromotive force is generated when two types of metals are joined and a temperature difference is applied to the junction is called the Seebeck effect. This is the principle of a thermocouple.

Problem: Which of the following descriptions regarding unsaturated polyester resins is not appropriate?

Options:

• A. Organic peroxides are often used as curing agents.
• B. Styrene monomer may be added to lower the viscosity.
• C. ✅ All must be heated to cure.
• D. Curing time can be adjusted by the amount of curing agent added.

Explanation:

Unsaturated polyester resins can be cured at "room temperature" by combining an accelerator and a curing agent. Since heating is not necessarily required in all cases, the description that "all must be heated" is incorrect.

Question: Select the inappropriate description regarding the prevention of poisoning by organic solvents in relevant laws and regulations of the Industrial Safety and Health Act.

Options:

• A. ✅ Use a dust mask.
• B. Use a supplied-air respirator.
• C. Use a gas mask for organic gases.
• D. Provide protective equipment in a number equal to or greater than the number of workers employed.

Explanation:
To prevent poisoning by organic solvents, it is necessary to use gas masks for organic gases or supplied-air respirators. Dust masks are masks for preventing dust (particulate matter), and since vapors or gases of organic solvents pass through them, they are inappropriate for organic solvent work.

Question: Select the statement that is NOT appropriate regarding the use of histograms.

Options:

• A. To detect process anomalies by looking at the shape of the distribution.
• B. To check if there are any out-of-specification items.
• ✅ C. To investigate factors affecting characteristics.
• D. To check for variation and bias.

Explanation:
A histogram is a graph for understanding the distribution state of data and is used to check for process anomalies, out-of-specification items, variation, and bias. However, investigating factors that affect characteristics is the role of cause-and-effect diagrams (fishbone diagrams) or experimental designs, and is not a purpose of a histogram.

Problem：Which of the following combinations of letter symbols and terms in JEM is incorrect?

Options：

• A. RSC Remote Supervisory Control
• B. SQC Sequence Control
• C. PMC Program Control
• D. ✅ AMC Feedback Control

Explanation：

Symbols such as "FBC" are used for feedback control. AMC is generally a symbol related to automatic operation, but its direct combination with feedback control in JEM standards is incorrect.

Question: Select the correct statement regarding the scale notation 1:1 used in technical drawing.

Options:

• A. ✅ Indicates full scale (actual size).
• B. Indicates reduced scale.
• C. Indicates 2x enlarged scale.
• D. Indicates both reduced and enlarged scales.

Explanation:
In technical drawing scale notation, 1:1 represents the same size as the actual object (full scale). Reduced scale (e.g., 1:2) is for drawing smaller than actual size, and enlarged scale (e.g., 2:1) is for drawing larger than actual size.

Question: According to JIS, which testing method represents hardness by pressing a diamond square pyramid and measuring the size of the resulting indentation?

Options:

• A. Shore hardness test
• B. ✅ Vickers hardness test
• C. Rockwell hardness test
• D. Brinell hardness test

Explanation:

The Vickers hardness test uses a diamond square pyramid indenter with a vertex angle of 136 degrees. Its feature is that the hardness value remains almost constant regardless of the test load, allowing for the measurement of a wide range of materials from extremely thin to very hard. On the other hand, Brinell uses a steel ball, Shore uses the rebound height, and Rockwell uses the depth of the indentation.