Positive Drive:
A positive drive is a type of power transmission system that ensures a positive and direct transfer of power from the driving source to the driven machine. It eliminates slip and ensures accurate speed ratios and torque transmission. In a positive drive system, the driving and driven components are directly connected, providing a reliable and efficient power transfer.

Types of Drives:
There are various types of drives used in mechanical engineering for power transmission. Some common types include rope drive, V-belt drive, chain drive, and gear drive. Among these options, the gear drive is considered a positive drive.

Rope Drive:
- Rope drive is a flexible power transmission system that uses ropes or cables to transmit power between two pulleys.
- It relies on the friction between the rope and the pulleys to transfer power.
- Rope drives are commonly used in applications where flexibility is required, such as in agricultural machinery or conveyor systems.
- However, due to the reliance on friction, slip and power loss can occur, making it less efficient compared to positive drives.

V-Belt Drive:
- V-belt drive is a type of flexible drive that uses V-shaped belts to transmit power between pulleys.
- It provides a compact and lightweight solution for power transmission.
- V-belt drives are commonly used in applications where noise reduction and shock absorption are required.
- However, like the rope drive, it relies on friction, which can result in slip and power loss.

Chain Drive:
- Chain drive is a type of power transmission system that uses roller chains to transmit power between sprockets.
- It provides a reliable and efficient power transfer, suitable for high torque applications.
- Chain drives are commonly used in industrial machinery, motorcycles, and bicycles.
- Although it is more efficient than rope and V-belt drives, it still has some inherent flexibility and potential for slip.

Gear Drive:
- Gear drive is a type of power transmission system that uses meshing gears to transmit power between shafts.
- It provides a positive and direct power transfer, ensuring accurate speed ratios and torque transmission.
- Gear drives are widely used in various applications, including automotive transmissions, industrial machinery, and power plants.
- The meshing of gears eliminates slip and provides a reliable and efficient power transmission.

Conclusion:
Among the given options, the gear drive is considered a positive drive. It offers a direct and reliable power transfer, ensuring accurate speed ratios and torque transmission. Unlike rope drive, V-belt drive, and chain drive, the gear drive eliminates slip and provides a more efficient power transmission system.