Answer :
To determine the correct sentences, we need to analyze each statement in the context of Ohm's Law, which is \( I = \frac{V}{R} \).
Let's break down each sentence step-by-step:
1. Sentence 1: If the current increases, then the resistance increases. Assume voltage is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the current \( I \) increases while voltage \( V \) is constant, then the equation \( I = \frac{V}{R} \) shows that \( R \) must decrease (because \( I \) is inversely proportional to \( R \)).
- Therefore, this statement is False.
2. Sentence 2: If the resistance decreases, then the current increases. Assume voltage is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the resistance \( R \) decreases while voltage \( V \) is constant, then \( I \) must increase (because \( I \) is inversely proportional to \( R \)).
- Therefore, this statement is True.
3. Sentence 3: If the voltage increases, then the resistance decreases. Assume current is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \), which can be rearranged to \( R = \frac{V}{I} \) when solving for \( R \).
- If the voltage \( V \) increases while current \( I \) is constant, then \( R \) must increase (because \( R \) is directly proportional to \( V \)).
- Therefore, this statement is False.
4. Sentence 4: If the voltage increases, then the current increases. Assume resistance is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the voltage \( V \) increases while resistance \( R \) is constant, then \( I \) must increase (because \( I \) is directly proportional to \( V \)).
- Therefore, this statement is True.
5. Sentence 5: If the voltage increases, then the current decreases. Assume resistance is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the voltage \( V \) increases while resistance \( R \) is constant, then \( I \) must increase (because \( I \) is directly proportional to \( V \)).
- Therefore, this statement is False.
Based on this analysis, the sentences that are true are:
- Sentence 2: If the resistance decreases, then the current increases. Assume voltage is constant.
- Sentence 4: If the voltage increases, then the current increases. Assume resistance is constant.
Thus, the correct answers are:
(2, 4).
Let's break down each sentence step-by-step:
1. Sentence 1: If the current increases, then the resistance increases. Assume voltage is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the current \( I \) increases while voltage \( V \) is constant, then the equation \( I = \frac{V}{R} \) shows that \( R \) must decrease (because \( I \) is inversely proportional to \( R \)).
- Therefore, this statement is False.
2. Sentence 2: If the resistance decreases, then the current increases. Assume voltage is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the resistance \( R \) decreases while voltage \( V \) is constant, then \( I \) must increase (because \( I \) is inversely proportional to \( R \)).
- Therefore, this statement is True.
3. Sentence 3: If the voltage increases, then the resistance decreases. Assume current is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \), which can be rearranged to \( R = \frac{V}{I} \) when solving for \( R \).
- If the voltage \( V \) increases while current \( I \) is constant, then \( R \) must increase (because \( R \) is directly proportional to \( V \)).
- Therefore, this statement is False.
4. Sentence 4: If the voltage increases, then the current increases. Assume resistance is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the voltage \( V \) increases while resistance \( R \) is constant, then \( I \) must increase (because \( I \) is directly proportional to \( V \)).
- Therefore, this statement is True.
5. Sentence 5: If the voltage increases, then the current decreases. Assume resistance is constant.
- According to Ohm's Law, \( I = \frac{V}{R} \).
- If the voltage \( V \) increases while resistance \( R \) is constant, then \( I \) must increase (because \( I \) is directly proportional to \( V \)).
- Therefore, this statement is False.
Based on this analysis, the sentences that are true are:
- Sentence 2: If the resistance decreases, then the current increases. Assume voltage is constant.
- Sentence 4: If the voltage increases, then the current increases. Assume resistance is constant.
Thus, the correct answers are:
(2, 4).