Which of the following is/are correct statement?
I. The apparent weight of a man in a lift going upward with some acceleration becomes more.
II. The apparent weight of a man in a lift going upward with some velocity become less.
III. The apparent weight of a man in a lift going upward with some acceleration become less.

Options

A. I is correct
B. Il is correct
C. III Is correct
D. All are correct

Answer

To solve the problem, we need to analyze each statement regarding the apparent weight of a man in a lift (elevator) under different conditions. Let's break down the statements one by one.

### Step 1: Analyze Statement I
**Statement I:** The apparent weight of a man in a lift going upward with some acceleration becomes more.

1. **Understanding Apparent Weight:** Apparent weight is the normal force (N) exerted by the lift floor on the person. When the lift accelerates upward, the person experiences an additional force due to the acceleration.
2. **Forces Acting on the Person:** The forces acting on the man are:
- Downward force due to gravity: \( mg \)
- Upward normal force: \( N \)
3. **Applying Newton's Second Law:**
- The net force acting on the man is given by:
\[ N - mg = ma \]
- Rearranging gives:
\[ N = mg + ma \]
4. **Conclusion for Statement I:** Since \( N = mg + ma \), the apparent weight \( N \) is greater than the true weight \( mg \). Thus, Statement I is **correct**.

### Step 2: Analyze Statement II
**Statement II:** The apparent weight of a man in a lift going upward with some velocity becomes less.

1. **Understanding Constant Velocity:** If the lift is moving upward with constant velocity, the acceleration \( a = 0 \).
2. **Forces Acting on the Person:** The forces are still:
- Downward force due to gravity: \( mg \)
- Upward normal force: \( N \)
3. **Applying Newton's Second Law:**
- The net force acting on the man is:
\[ N - mg = 0 \]
- Rearranging gives:
\[ N = mg \]
4. **Conclusion for Statement II:** Since \( N = mg \), the apparent weight is equal to the true weight. Thus, Statement II is **incorrect**.

### Step 3: Analyze Statement III
**Statement III:** The apparent weight of a man in a lift going upward with some acceleration becomes less.

1. **Understanding Acceleration Again:** As analyzed in Statement I, when the lift accelerates upward, the apparent weight increases.
2. **Forces Acting on the Person:** The same forces apply as before:
- Downward force due to gravity: \( mg \)
- Upward normal force: \( N \)
3. **Applying Newton's Second Law:**
- The net force is:
\[ N - mg = ma \]
- Rearranging gives:
\[ N = mg + ma \]
4. **Conclusion for Statement III:** Since \( N = mg + ma \), the apparent weight is greater than the true weight. Thus, Statement III is **incorrect**.

### Final Conclusion
Based on the analysis:
- Statement I is **correct**.
- Statement II is **incorrect**.
- Statement III is **incorrect**.

Therefore, the only correct statement is Statement I.

### Final Answer
The correct answer is: **Only Statement I is correct.**

---