Free Mechanical Aptitude Test Practice Questions and Answers

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 convertors 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 correct answer is A.

The pendulum is moving backwards; therefore, the car is accelerating in the opposite direction. That happens when an object is in an accelerating system, in the same way you feel yourself pulled backwards when the car is speeding up or forwards when it is braking.
Remember the physical principle: When an object is within an accelerating system (another object that accelerates or decelerates), the force on the inner object will be in the direction opposite to the acceleration.

Note: Deceleration is considered a backwards acceleration.

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 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:

The correct answer is C.

This question can be solved in a straightforward calculation of the volume of the granaries, using the formula of a cylinder’s volume:

V = π x R2 x H

Where: π = 3.14, R is the cylinder’s radius, and H is the cylinder’s height.

Calculating:
Answer A: 4 x π x 52 x 10 = 4 x π x 25 x 10 = 3.14 x 100 x 10 = 3,140
Answer B: π x 52 x 40 = π x 25 x 40 = 3.14 x 1,000 = 3,140

However, there is no need for such lengthy calculations. As we can see, the height of the cylinder affects the volume of a cylinder linearly, meaning 4 cylinders with height H are equal in volume to one cylinder with height 4H:

V (4 short) =4 x {π x R2 x H} = 4 x π x R2 x H
V (1 tall) = π x R2 x 4H = 4 x π x R2 x H

Remember the physical principle: The volume of a cylinder is linearly dependent on its height.

Note: The same does NOT apply to the cylinder’s radius since the R in the formula is squared. In that case, the volume of one cylinder with a radius of 2R will be equal to the volume of four cylinders with a radius R. The volume of one cylinder with a radius of 4R will be equal to the volume of sixteen cylinders with a radius R.

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 figure in B has a wheel to reel in the rope. However, this wheel does nothing to divide the force and only changes the pulling from a linear motion in A to a circular motion in B.
Remember the physical principle: In a pulley system, the wheels that reduce applied force are supporting wheels, not wheels that only change the motion’s direction.

Answer:

The correct answer is B.

A band connects the two wheels on the left; therefore, the top wheel will spin counter-clockwise. The two wheels at the top are connected by a rod; thus, both rotate in the same direction. The wheel in question is connected by a band to the top right wheel and influenced by its rotation.

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.

A seesaw is an example of a first-class lever, where the fulcrum is between the effort and load. For the seesaw to be balanced, the torque applied by the acrobat must increase. Since the weight of the acrobat is constant, the only way to increase the input torque is by increasing the distance from the fulcrum.

Moving in direction B will shift the acrobat’s center of gravity farther from the fulcrum, resulting in greater torque, thereby balancing it.

Answer:

The correct answer is A.

Pendulum A has a shorter string; therefore, it will swing faster.

Intuitively, the shorter pendulum has less distance to travel in every cycle and, therefore, will move faster.

The bob's mass is irrelevant since the pendulum is affected by gravity, which applies the same acceleration on each body, regardless of its mass. Both bobs accelerate the same; therefore, their mass does not affect the pendulum’s movement.

Remember the physical principle: The only thing that determines how fast a pendulum will swing is its string length.