The correct order of iron-ore mines from south-west to north-east is:
- Kudremukh (iv) – located in the south-western part of India, in Karnataka.
- Ballari (iii) – located to the north-east of Kudremukh, also in Karnataka.
- Bailadila (i) – located further north in Chhattisgarh.
- Mayurbhanj (ii) – located in the north-eastern part, in Odisha.
Hence, the correct sequence is (iv), (iii), (i), and (ii), which corresponds to option (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 \( r \).