Which of the following are quantised?

Options

A. Going upstairs on a ladder.
B. Slippiing down a slope.
C. The movement of a second's hand in a watch.
D. The movement of fare meter in a taxi.

Answer

To determine which of the given options are quantized, we need to understand the concept of quantization. Quantization refers to the restriction of a variable to certain discrete values or states. In simpler terms, it means that a variable can only take on specific values, rather than any value within a range.

### Step-by-Step Solution:

1. **Understand Quantization**:
- Quantization means that certain variables can only take on specific, discrete values. For example, energy levels in an atom are quantized, meaning electrons can only exist in certain energy states.

2. **Evaluate Each Option**:
- **Option A: Going upstairs on a ladder**:
- When you go up a ladder, you can only step on the rungs, which are discrete points. You cannot stand halfway between two rungs. Therefore, this is quantized.

- **Option B: Slipping down a slope**:
- When slipping down a slope, you can cover any distance continuously (e.g., 2.5 meters, 3.7 meters). There are no discrete steps or values. Therefore, this is not quantized.

- **Option C: Movement of the second hand in a watch**:
- The second hand moves in fixed increments, completing one full rotation in 60 seconds. Each tick represents a discrete unit of time (1 second). Thus, this is quantized.

- **Option D: Movement of fare meter in a taxi**:
- The fare meter can vary continuously based on distance traveled and does not have fixed increments. Therefore, this is not quantized.

3. **Conclusion**:
- The options that are quantized are:
- **Option A: Going upstairs on a ladder**
- **Option C: Movement of the second hand in a watch**

### Final Answer:
- The quantized options are A and C.