Free Mechanical Aptitude Test Practice Questions and Answers [2025]

Answer:

The correct answer is C.

The question asks for the device that is used to store electrical energy. Let's go through the options one by one.

A. A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element.

It is primarily used to limit current and/or divide voltages in electrical circuits. It doesn't store energy but rather dissipates it in the form of heat.

B. A diode is a semiconductor device that allows current to flow in one direction but not another. It is commonly used for rectification (converting alternating current to direct current), among other applications.While it can be part of circuits that store energy, the diode does not.

C. A capacitor is an electrical component that stores and releases electrical energy in a circuit. It stores energy by accumulating an internal imbalance of electric charge between its plates, and it can release that stored energy when needed. Therefore, it is the device used to store electrical energy.

D. An inductor is an electrical component that stores energy in a magnetic field when an electrical current is passed through it. While it does store energy, it is not electrical energy per se but rather magnetic energy.

Moreover, it's commonly used to store energy temporarily and is often used in filtering applications and energy storage in inductive-based converters, but is not primarily designed for electrical energy storage in the way a capacitor is.

Based on the above explanations, the correct answer is C - Capacitor. This is the device that is specifically designed to store electrical energy in an electric field between its plates.

Answer:

The correct answer is B.
In a series circuit, the total resistance is the sum of individual resistances:
Rtotal =R1+R2=4Ω+6Ω=10Ω.

Answer:

The correct answer is C. There are two processes involved in a two-stroke engine: Compression stroke and Power stroke.

In compression stroke, the inlet port opens and the air-fuel mixture enters the chamber, and the piston moves upwards, compressing the mixture.

In the power stroke, the heated gas exerts pressure, and the piston moves downwards during the expansion. Therefore, only C is the correct choice. The following figure summarizes the two-stroke engine cycles.

Answer:

The correct answer is B.

The processor (CPU) reads the stored program in Random Access Memory (ROM) with the help of the operating system that is downloaded in Read-Only Memory (ROM).

The processor makes logical decisions based on the PLC program. However, these decisions are executed with the help of the I/O module. Therefore, B is the correct choice, and A, C, and D are incorrect.

Answer:

The movement of the tractor can be paralleled to a circular motion problem in which the one travelling along the outer edge of the turn has a greater distance to cover.

Such is the case of chain 2. In contrast, chain 1 stays almost completely still, as it is the axis of the turn. 

Therefore, chain 1 has to move slower in order for the tractor to move in the marked direction. The correct answer is A = 1.

Answer:

The correct answer is C.

Gravity is applied to both balls equally, and the vertical distance they ought to pass is identical. The time needed for both balls to hit the ground is identical, regardless of the horizontal velocity component.

Therefore, it can be deduced that both balls will hit the ground simultaneously.

Remember the physical principle: When an object falls under the influence of gravity, its vertical velocity does not depend on the horizontal velocity.

Answer:

The correct answer is A.

In picture A, the bird flies with her wings backward, minimizing the contact surface with the wind and creating less resistance.

The bird in picture B extends with her wings and legs perpendicular to the wind direction, thus increasing the contact surface with the wind, creating much more resistance.

The same phenomenon makes a crumpled piece of paper fall faster than an open sheet of paper, which has more surface area and more resistance.

Remember the physical principle: The larger the surface of contact with air/wind, the more resistance (force) is created.

Kinematics questions may ask about basic concepts, and movements, and sometimes may include different types of calculations. Kinematics questions can also be found in our Ramsay Mechanical PrepPack, Bennett PrepPack, Wiesen PrepPack, and Delta BMAR PrepPack.

Answer:

For the scale to balance, the total of torques on either side of the scale must be equal. Assigning the numbers 1, 2, and 3 to the weights of 5kg, 6kg, and the "?" weight, respectively, we have our torque equation: T1 + T2 = T3.

Each torque is by definition T = W x L, where W is the weight and L is the distance from the fulcrum. Recall that W = M x g, where M is the mass and g is the gravitational constant.

M1 x g x L1 + M2 x g x L2 = M3 x g x L3

We can simplify by dividing both sides by g:

M1 x L1 + M2 x L2 = M3 x L3

Our givens are M1 = 5kg, L1 = 12cm, M2 = 6kg, L2 = 15cm, M3 = ?, L3 = 20cm. Substituting the values given in the question in the equation:

5kg x 12cm + 6kg x 15cm = M3 x 20cm

Now solve like a regular equation (multiplying before adding and isolating M3), just do not forget to mind the units as well:

(5 x 12) [kg x cm] + (6 x 15) [kg x cm] = M3 x 20cm

Multiply the figures on the left side:

60 [kg x cm] + 90 [kg x cm] = M3 x 20cm

Add the figures on the left side:

150 [kg x cm] = M3 x 20cm

Divide by 20cm to isolate M3:

M3 = 150 [ kg x cm] / 20cm

M3 = (150/20) [kg x cm / cm]

=> M3 = 7.5kg

Therefore, 7.5 kg is the correct answer.

Answer:

A pressure difference on both sides causes the bending of the partition. That pressure difference is determined by the level of water in each container.

The pressure is determined by the height of the water on the container – the higher the water – the greater the pressure.

In A, the partition bends to the right, suggesting the pressure is greater on the left side. That is consistent with the higher water level on the left side.

In B, the partition is flat, suggesting there is no pressure difference between its two sides despite the different water levels. Therefore, this answer is false.

In C, the partition bends to the left, suggesting the pressure is greater on the right side. That contradicts the higher water level on the left side. Therefore, this answer is also false.

Answer:

The correct answer is A.

The question asks us to compare the air pressure inside two balloons: fully inflated (Balloon A) and half-inflated (Balloon B).

Air pressure in a balloon is generally determined by the amount of air it contains and the volume it occupies.

A fully inflated balloon is generally stretched more tightly than a half-inflated balloon, and therefore, the air molecules inside are compressed into a smaller volume than they would be in a half-inflated balloon. This compression results in higher air pressure.

So, in this scenario, Balloon A, which is fully inflated, would generally have more air pressure inside it than Balloon B, which is only half-inflated.

Answer:

The correct answer is 2.

In order to answer questions of this type, we need to be familiar with the concept of gear ratio, also known as transmission ratio.

Gear ratio is defined as the ratio between the wheel upon which the force is applied and the wheel to which the force is transmitted.

Ninput    = the number of teeth in the driver gear (driver cogwheel)
Noutput  = the number of teeth in the driven gear (driven cogwheel)

->  Gear ratio = Noutput/Ninput

We can see from the diagram that the driver cogwheel in bicycle A is bigger than in bicycle B, whilst the driven cogwheel remains the same.

In accordance with the formula, we can see that the transmission ratio of bicycle B is greater than the transmission ratio of bicycle A (the transmission ratio is inversely proportional to the size of the driver cogwheel). Thus, the correct answer is bicycle B.

In this type of question, it might be easier for you to think of the transmission ratio in a more abstract way. For example, "When I turn the driver cogwheel once, how many times will the driven cogwheel turn?";

in this case, when the driver cogwheel in bicycle A turns once, it will cause more turns of the driven cogwheel in comparison to bicycle B. 

Answer:

The correct answer is (C) – Left with the same velocity.

When raft A moves left, it applies a force on the 5-toothed gear attached to it, causing it to rotate clockwise.

Since the system given above consists of an even number of 4 meshed gears, the 5-toothed gear attached to raft B will rotate anti-clockwise.

This movement will apply a force on raft B, causing it to move left as well. This eliminates answers B, D, and E.

When two gears of equal number of teeth are combined, they rotate at the same velocity.  Since the first and last gears of this meshed gear system have the same number of teeth, they will move at the same velocity.

Therefore, Left with the same velocity is the correct answer.

Answer:

The correct answer is A.

When contact is made between the rack (toothed belt) and the cogwheels, a conversion occurs from linear to angular velocity. The location of the point of contact is critical.

The point of contact between the red cogwheel and the rack is in the lower part of the red cogwheel. The counterclockwise angular velocity induces a linear velocity to the right.

The point of contact between the grey cogwheel and the rack is in the grey cogwheel's upper part. The linear velocity to the right (determined by the rack) induces an angular velocity in a clockwise direction.

The process can be exemplified by the blue arrows, which show where each part of the wheel is moving under the rotation conditions:

Simple Machine questions – which mostly include either wheels and pulleys or cogwheels, usually require prediction about outcomes of specific actions – either movement of objects, direction of rotation, or other options.

Answer:

The correct answer is B.

We are asked in this question to determine which bear will get closer to the mirror.

When a spring is compressed, energy is stored in the spring. The more one compresses the spring, the larger the amount of energy that gets stored in the spring. When the spring is released, so is the energy; this energy then causes the spring to expand.

The larger the amount of energy, the greater the force expanding the spring. This, in turn, causes the spring to expand farther. Therefore, the more one compresses a spring, the farther the spring will expand when released.

Since Spring B is more compressed than Spring A, it will reach farther when released. Therefore, choice B is the correct answer.

Answer:

A seesaw is an example of a first-class lever, where the fulcrum is in the middle and both forces (effort and load) are applied onto both sides of it.

In order for the seesaw to be balanced, the torque applied by the dancer must increase. Since the weight of the dancer remains the same, the only way to increase the input torque is by increasing the distance from the fulcrum.

In position B, even though the location of the dancer’s hands is the same as in A, the body’s center of mass is more distant from the fulcrum, and thus the input torque would be greater.

This will make it more likely for the seesaw to be balanced.

The correct answer is B.