Valero Mechanical Aptitude Practice Test

These questions are part of the practice quiz. Start practicing

• The measuring unit for electric charge is which of the following?
• If pressure is halved at constant temperature, what happens to the volume?
• Which term describes a resistor whose value can be adjusted in a circuit?
• What best describes how a welded joint is formed?
• What is the SI unit used to measure electrical power?
• A belt drive uses a 4-inch driver pulley to drive a 12-inch driven pulley. What is the speed ratio of driven to driver?
• What unit describes a hydraulic pump displacement per revolution, as used in the specification 100 in^3/rev?
• Which equation expresses power in terms of current and resistance?
• What does "Grade 8" indicate for a bolt?
• A shaft has a tolerance of 0.500 ± 0.005 inches and a hole has a tolerance of 0.500 ± 0.003 inches. Is a clearance fit guaranteed?
• What is the correct use of a torque wrench in assembly?
• To find the current when you know voltage and total resistance, you
• Which electrode is called the anode in a polarized device?
• Which component allows changing its resistance to adjust circuit current?
• In a parallel circuit, adding a separate branch with a load affects total current by:
• Which symbol is commonly used to denote electrical power in the equations?
• In a hydraulic cylinder, if the piston diameter doubles while pressure remains the same, output force increases by what factor?
• Which constant is used in the formula for the area of a circle?
• Convert 50 miles per hour to feet per second.
• Which statement best describes a shaft-hole fit that can be a mix of clearance and interference depending on actual sizes?
• Which instrument is used for measuring electric charge?
• When pressure increases at constant temperature, what happens to the gas volume?
• With an even number of gears, the first and last gear rotate in which relation?
• Which component is commonly used as a power source in electrical circuits?
• Which material is considered a good conductor?
• What does tolerance mean in manufacturing?
• The electrode from which current flows out of a polarized electrical device is called the
• Which statement describes Boyle's Law when the temperature and amount of gas are constant?
• What does NPT stand for in pipe fittings?
• In mechanics, which statement correctly defines how work relates to force and distance?
• In most circuits, which component is considered the energy source?
• Electric current tends to take the path of what?
• What is a screwed coupling?
• If two equal volumes contain water and ice, which weighs more?
• A single-start screw has a lead of 1.5 mm. How far does it advance per full turn?
• In a hydraulic system, with the piston area fixed, how does output force change as pressure increases?
• In electrical diagrams, what symbol typically represents a motor?
• The electrode from which current flows into a polarized electrical device is called the
• A lever has an effort arm of 6 cm and a load arm of 3 cm. If the input force is 12 N, what is the load force at the end?
• The area of a circle with a 6-inch diameter is approximately what value?
• What is the relationship between pressure and volume according to Boyle's Law?
• What remains constant in Boyle's Law?
• What is the standard unit for pressure in the imperial system?
• Current in a circuit with multiple paths of different resistances splits among paths
• What is the primary purpose of lubrication in a mechanical system?
• Which component converts electrical energy into light and heat?
• In a hydraulic system, if the piston diameter remains constant and pressure increases, what happens to output force?
• In a DC circuit with a 12 V supply and a 10 Ω resistor, what is the current?
• What does a mixed fit indicate about shaft and hole tolerances?
• Two resistors, 6 Ω and 3 Ω, connected in parallel have an equivalent resistance of:
• For a circle with diameter 2 inches, which statement about its cross-sectional area is correct?
• What is a common cause of gear wear in drive systems?
• For a lever where the effort arm is twice the load arm, what is the mechanical advantage?
• What is the first step in diagnosing a malfunctioning machine?
• What is the primary difference between a bolt and a screw?
• If pressure triples while temperature remains constant, the volume becomes what fraction of its original value?
• In a clearance fit, which statement is true?
• A tape measure reads 7.25 inches. Convert this to millimeters.
• After verifying that power is supplied, what is the next step in diagnosing a malfunctioning machine?
• In a gear train with driver 24 teeth and driven 12 teeth, what is the speed of the driven gear relative to the driver?
• Define mechanical advantage in a simple machine.
• In a hydraulic system, what is the primary mechanism by which an impeller increases a fluid’s energy?
• What usually causes belt drive wear or slipping?
• Which statement best describes an open circuit?
• A circuit that includes a resistor stores how much energy compared to an identical circuit without a resistor?
• In screw terminology, what does lead refer to?
• In a pulley system with multiple rope sections supporting the weight, the lifting force is
• A megohmmeter is typically used to measure insulation resistance.
• What is the function of a cam in mechanical systems?
• What term describes the difference in electric potential between two points?
• A circuit has a 12-volt source connected to a 4-ohm resistor. The current is:
• If the electrical supply is 60 Hz, what is the period of one cycle in seconds?
• Which component can break a circuit by interrupting the current or diverting it from one conductor to another?
• In a parallel circuit, the total current equals
• What parameter does an ohmmeter directly measure?
• If a flow control valve reduces flow from 120 gpm to 60 gpm with the same upstream pressure, what is the percent reduction in flow?
• If a gas at constant temperature is compressed to half its original volume, what happens to the pressure?
• What is the SI unit of electrical resistance?
• In a series circuit, the sum of the voltage drops across all components equals the
• The variable representing voltage is
• Impedance is measured in which unit?
• In a simple gear pair with a driver having 20 teeth and a driven gear with 40 teeth, what is the speed ratio of the driven gear to the driver?
• If an ohmmeter is connected across an inductor and the pointer reads zero ohms, the inductor is:
• In a simple gear pair, the speed ratio of the driven gear to the driver is equal to which of the following?
• Which statement about hydraulic systems is true?
• Which formula gives voltage across a resistor?
• Pressure multiplied by area yields which physical quantity?
• Which expression correctly defines resistance?
• Which instrument is used to measure the voltage across a component?
• What instrument is used for measuring electric power?
• Under constant amount and temperature, if volume is reduced, pressure increases.
• In a parallel circuit containing a copper conductor and an insulating rubber branch connected to a battery, which branch carries current?
• What is the function of a check valve?
• The hazardous component of power is the __________, not the voltage.
• Which quantity will change according to how distant the point is from the center?
• In a pneumatic system, what is the typical working medium?
• Which symbol is commonly used to denote current in the equations?
• To decrease the current through a specific resistor in a parallel network, you should:
• When an extra resistor is added in parallel to a circuit, the total resistance:
• Adding resistors in series will cause what to occur in the circuit?
• Which unit represents energy?
• Which quantity is measured in Coulombs?
• In a simple circuit, current flows from which direction to which?
• Which term describes a circuit path that is broken and prevents current flow?
• What is the primary purpose of a gasket?
• With a single pulley attached to the ceiling, the force needed to lift an object is
• If a device has 9 Ω resistance and carries 2 A, what is the power dissipated?
• Which unit is used to measure energy?
• Which statement correctly describes Boyle's Law?
• The variable representing current is
• If three resistors of 6 Ω, 3 Ω, and 2 Ω are in a series circuit, their total resistance is
• What happens to the total resistance when an additional resistor is added in series?
• In lubrication practice, what is the purpose of wetting?
• If an 8-ohm resistor has 12 V applied, the current is 1.5 A. If the voltage is increased to 24 V, the current becomes:
• To find the voltage drop across a component, you multiply the current by
• With an odd number of gears, do the first and last gears rotate in the same direction?
• In a parallel circuit, the potential difference across each branch is
• In a parallel circuit with four branches: A=50 Ω, B=30 Ω, C=30 Ω, D=10 Ω, which branch draws the most current?
• A hydraulic pump has a displacement of 100 in^3 per revolution and a volumetric efficiency of 90%. What is the actual output per revolution?
• A voltmeter is used to measure which electrical quantity?
• In mechanical fits, what is a clearance fit?
• Which component is used primarily to limit current by providing resistance?
• Which property explains why water weighs more than ice at equal volumes?
• To increase output force without changing pressure, you should
• In a circuit where a copper thread and a rubber thread are connected in parallel to a battery, which path carries the current?
• Which gas law applies when the temperature is constant and the amount of gas remains fixed?
• Which of the following is a unit of electric potential?
• Which state of a switch completes the circuit, allowing current to flow?
• In mechanics, power is defined as what?
• To maintain equal linear velocity among gears, the smaller gear must rotate faster.
• If a constant force doubles while the distance remains the same, what happens to the work done?
• What is the formula for the area of a circle in terms of diameter D?
• What is a bearing used for in rotating machinery?
• If you double the pressure while maintaining temperature, the volume becomes
• The difference in electric potential between two points is called:
• Which feature enables assembly and disassembly of a screwed coupling?
• When more resistors are added in parallel, what happens to the circuit's total resistance?
• Which condition is required for Boyle's Law to hold?
• In a series circuit, adding another resistor causes the total resistance to:
• If a screw has a lead of 1.25 mm, what is the axial advance per complete turn?
• The variable representing Watts is?
• In a hydraulic system, what energy forms does the impeller convert rotational energy into to raise the fluid’s energy?
• Two switches in parallel on one side of a battery will cause a ________.
• Which expression represents Ohm's law?
• The time for one complete cycle of a 60 Hz electrical supply is approximately
• Which electrical component stores energy in an electric field?
• To compute current from the given relationships, which two quantities are needed?
• How do we find the area of a rectangle?
• To obtain the force needed to lift a weight in a pulley system, you
• What is the measuring unit for electric capacitance?
• In engineering drawing, what does a section view show?
• Lowering the resistance in a series circuit will cause the current to
• If you compress a gas to one quarter of its original volume at constant temperature, the pressure becomes
• In basic energy accounting, what is the relationship between input energy and output energy in an ideal machine?
• Which tool is best for checking the inside diameter of a hole for roundness?
• A pipe has a 2-inch diameter and carries water at 3 ft/s. What is the cross-sectional area in square inches and the approximate volumetric flow in ft^3/s?
• A lamp has power 4 W and a resistance of 16 Ω. What is the current when operated at its rated voltage?
• A hydraulic cylinder has a piston diameter of 4 inches. If system pressure is 1000 psi, what is the axial force on the piston?
• Which component converts electrical energy into light in typical circuits?
• What is the main function of a flywheel?
• What is an interference fit?
• In a parallel network, the total resistance is less than the smallest resistor.
• Megohmmeters are normally used to test which property?
• A weight of 200 N is supported by 4 rope sections. What lifting force is required?
• An electric current is the rate at which what quantity flows?
• How do you calculate current flow?
• Three resistors of 20 Ω, 5 Ω, and 2 Ω are connected in parallel. Their total resistance is
• A series circuit contains a 6 Ω resistor and a 4 Ω resistor connected to a 24 V source. The current in the circuit is :
• A lever has an effort arm of 8 cm and a load arm of 2 cm. What is the theoretical mechanical advantage?
• Power factor can only be
• If a system with multiple gears aims for equal linear velocity, what must you do regarding gear sizes?
• Which instrument is used to measure electrical resistance?
• The rate at which electric energy is transferred by an electric circuit is defined as:
• A tube has an outer diameter of 5 inches and a wall thickness of 0.5 inches. What is the inside diameter?
• If a relief valve is set to release at 1500 psi and system pressure reaches 1600 psi, what happens?
• If pressure decreases from 2 atm to 1 atm at constant temperature, what happens to the volume if the initial volume is V0?
• In circular motion, which quantity changes with distance from the center?
• Which law describes the inverse relationship between pressure and volume of a gas at constant temperature?
• In a series circuit, the current is
• What is the area of a circular piston with a diameter of 4 inches?
• In a circuit, current flows from
• An ammeter measures which quantity?
• Which symbol is commonly used to denote voltage in the equations?
• The force needed to lift with a pulley will
• Which device allows current to flow primarily in one direction?
• Using a single ceiling pulley changes the lifting force such that it is
• Which unit is the standard for electric potential difference?
• What is the cross-sectional area of a circle with a diameter of 2 inches?
• In a hydraulic system, with fixed piston area, how does output force change as pressure increases?
• When a wheel is ________, its rotation will hold it in place on an axle due to the air moving on its sides.
• Which formula gives current?