You are a travel enthusiast. You strongly feel that travelling is essential to a person’s development as it increases knowledge and widens intellect. Write an article for your school magazine stressing on the importance of travel. You may use the cues given along with your own ideas to compose the article. You are Dipanshi/Dipesh of Class XII-C.


A battery of emf \( E \) and internal resistance \( r \) is connected to a rheostat. When a current of 2A is drawn from the battery, the potential difference across the rheostat is 5V. The potential difference becomes 4V when a current of 4A is drawn from the battery. Calculate the value of \( E \) and \( r \).