Pressure of a gas in a vessel can be measured by

Options

A. Barometer
B. Manometer
C. Stalgometer
D. All the above

Explanation

To solve the question "Pressure of a gas in a vessel can be measured by," we will analyze each of the options provided and determine which instrument is appropriate for measuring the pressure of a gas in a vessel.

### Step-by-Step Solution:

1. **Understanding the Options**:
- **Option A: Barometer** - A barometer is an instrument that measures atmospheric pressure. It is not used for measuring the pressure of a gas in a closed vessel.
- **Option B: Manometer** - A manometer is specifically designed to measure the pressure of gases in a vessel. It can measure the pressure difference between the gas in the vessel and the atmospheric pressure.
- **Option C: Stalgometer** - A stalgometer is an instrument used to measure surface tension, not gas pressure. Therefore, it is not relevant to this question.
- **Option D: All** - This option suggests that all the instruments can measure the pressure of a gas in a vessel, which is incorrect based on the analysis of the previous options.

2. **Evaluating the Correct Option**:
- From the analysis, we see that the barometer and stalgometer do not measure the pressure of a gas in a vessel. The only instrument that does this is the manometer.

3. **Conclusion**:
- The correct answer to the question is **Option B: Manometer**. It is the instrument used to measure the pressure of a gas in a vessel.

### Final Answer:
**The pressure of a gas in a vessel can be measured by a Manometer (Option B).**