Odd man out in Planar Mechanisms: Hooke’s Universal Joint

Planar mechanisms are mechanical systems that operate in a single plane of motion. They consist of interconnected links that undergo relative motion, enabling the transfer of forces and motion. While most planar mechanisms share common characteristics, there is one that stands out as the odd man out - Hooke's Universal Joint.

1. Plate Cam and Follower:
- A plate cam and follower mechanism is a type of planar mechanism used to convert rotary motion into reciprocating or oscillating motion.
- It consists of a rotating cam, which is a specially shaped disc, and a follower that tracks the cam's contour.
- As the cam rotates, the follower moves in response to the changing shape of the cam profile.
- This mechanism is commonly used in engines, machines, and automotive applications for valve actuation, fuel injection, and other similar functions.

2. Slider Crank Mechanism:
- The slider crank mechanism is another widely used planar mechanism that converts rotary motion into linear motion.
- It consists of three main components: a crank, a connecting rod, and a slider.
- The crank rotates, causing the connecting rod to move in a circular path.
- The slider, connected to the connecting rod, undergoes linear motion along a straight line.
- This mechanism is commonly found in engines, piston-driven machines, pumps, and other applications that require converting rotational motion into linear motion.

3. Hooke's Universal Joint:
- Hooke's universal joint is a mechanism used to transmit motion between two shafts that are not aligned.
- It consists of two yokes connected by a cross-shaped element, allowing the joint to accommodate misalignment.
- This mechanism enables the transmission of rotary motion from one shaft to another, even when they are at an angle to each other.
- It is commonly used in automotive drive shafts, steering systems, and other applications where misalignment is present.

4. Odd Man Out - Hooke's Universal Joint:
The odd man out in the given options is Hooke's Universal Joint because it is not primarily a planar mechanism. Unlike the plate cam and follower and the slider crank mechanism, which operate in a single plane, Hooke's universal joint allows motion transmission between non-aligned shafts, making it a versatile mechanism for accommodating misalignment.

While Hooke's universal joint can be included in discussions about mechanical systems, it is different from the other options in terms of its purpose and application. The plate cam and follower and the slider crank mechanism are specifically designed to convert rotary motion into different types of linear or reciprocating motion within a single plane.

Therefore, the correct answer is option 'B' - Hooke's universal joint.