DAA - Defence Aptitude Assessment Mechanical Comprehension Principles Questions and Answers

Question 1

In the gear system shown, Gear A has 10 teeth and turns clockwise. Gear B has 20 teeth, and Gear C has 5 teeth. Which of the following statements is true?

Accepted Answer

Gear C will turn clockwise and faster than Gear A.

Answer

Gear C will turn anti-clockwise and slower than Gear A.

Answer

Gear C will turn clockwise and at the same speed as Gear A.

Answer

Gear C will turn anti-clockwise and faster than Gear A.

Question 2

A person is using a crowbar to lift a heavy crate. To get the maximum mechanical advantage and make the lift as easy as possible, where should the fulcrum be placed?

Accepted Answer

As close as possible to the crate.

Answer

Exactly in the middle of the crowbar.

Answer

As close as possible to the person's hands.

Answer

It does not matter where the fulcrum is placed.

Question 3

Four pulley systems are lifting an identical weight. System A has one fixed pulley. System B has one fixed and one movable pulley. System C has two fixed and two movable pulleys. System D has three fixed pulleys. Assuming the pulleys and ropes are weightless and frictionless, which system requires the least amount of effort to lift the weight?

Accepted Answer

System C

Answer

System A

Answer

System B

Answer

System D

Question 4

The image shows four interconnected containers of different shapes. If water is poured into the container on the far left, what will be the final water level in all four containers when the water comes to rest?

Accepted Answer

The water level will be the same in all four containers.

Answer

The water level will be highest in the widest container.

Answer

The water level will be highest in the narrowest container.

Answer

The water level will be highest in the container on the far right.

Question 5

Which of the following designs for a vehicle would be the most stable and least likely to tip over while cornering?

Accepted Answer

A low center of gravity and a wide base.

Answer

A high center of gravity and a wide base.

Answer

A high center of gravity and a narrow base.

Answer

A low center of gravity and a narrow base.

Question 6

Two pendulums are set to swing. Pendulum A has a string length of 1 metre and a mass of 10kg. Pendulum B has a string length of 2 metres and a mass of 5kg. Which pendulum will have the shorter period (i.e., swing back and forth more quickly)?

Accepted Answer

Pendulum A, because it is shorter.

Answer

Pendulum B, because it is lighter.

Answer

They will have the same period.

Answer

Pendulum A, because it is heavier.