Initial Cost High Moderate Very High Very High Running Cost High (fuel) High (fuel) Very Low Low (fuel) Efficiency 35-40% 30-45% 85-90% 30-40% Environmental Air pollution, CO$_2$ Air pollution, Noise Eco-friendly (dam impact) Radioactive waste, no CO$_2$ Flexibility Moderate High (quick start) High (load changes) Low (base load)

6. Nuclear Power: Safety & Impacts

Safety Measures

Containment Structure: Multiple barriers to prevent radiation release.
Redundant Systems: Multiple backup systems for critical functions.
Control Rods: Rapid shutdown (scram) capability.
Emergency Core Cooling Systems (ECCS): To prevent meltdown.
Waste Management: Secure storage and disposal of radioactive waste.
Strict Regulations & Training: Continuous monitoring and highly trained personnel.

Environmental Impacts

Radioactive Waste: Long-term storage challenge.
Thermal Pollution: Discharge of heated water into water bodies.
No Greenhouse Gas Emissions: During operation (major advantage).
Risk of Accidents: Though low, can have catastrophic consequences (e.g., Chernobyl, Fukushima).
Uranium Mining: Environmental disturbance and potential radiation exposure.

7. Belt Drives

Working Principles

Transmit power between two shafts using an endless belt passing over pulleys. Power is transmitted due to the friction between the belt and pulley surfaces.

Velocity Ratio

Ratio of the speed of the driver to the speed of the driven pulley.

$ \frac{N_2}{N_1} = \frac{d_1}{d_2} $ (for open belt drive, no slip)

Where $N_1, N_2$ are speeds of driver and driven pulleys, $d_1, d_2$ are pitch diameters.

Power Transmission

$ P = (T_1 - T_2)v $

Where $T_1$ is tension in tight side, $T_2$ is tension in slack side, $v$ is belt velocity.

Slip

Relative motion between the belt and pulley surface. Reduces the velocity ratio and transmitted power.

$ \text{Slip percentage} = \frac{N_1 d_1 - N_2 d_2}{N_1 d_1} \times 100 $

Creep

Elastic phenomenon due to stretching of the belt on the tight side and contracting on the slack side. Also reduces the velocity ratio slightly, even without gross slip.

8. Rope Drives

Working Principles and Applications

Similar to belt drives but use ropes (fiber or wire) and grooved pulleys (sheaves). Suitable for transmitting large amounts of power over long distances.

Applications: Cranes, hoists, textile machinery, power transmission over long distances, elevators.
Better for shock absorption than belts.

9. Gear Drives

Types of Gear Drives

Transmit power between shafts by means of meshing teeth, ensuring positive drive without slip.

Spur Gears: Teeth parallel to the axis, for parallel shafts. Simplest type.