Which of the following device is based upon magnetic effect of electric current ?

Question

Accepted Answer

Option 3, the electric bell, is based upon the magnetic effect of electric current. Here's a detailed explanation:

1. **Explanation for Option 3 (Electric Bell):**
   - An electric bell operates on the principle of electromagnetism, which is a direct application of the magnetic effect of electric current. When electric current flows through the coil of wire in the bell, it creates a magnetic field. This magnetic field attracts a metal armature, causing it to move and strike the bell, producing sound. Once the armature moves, it breaks the circuit, causing the magnetic field to collapse and the armature to return to its original position, ready to repeat the cycle. This process clearly demonstrates the use of the magnetic effect of electric current.

2. **Explanation for why other options are incorrect:**

- **Option 1 (Electric Bulb):**
     - An electric bulb works on the principle of the heating effect of electric current, not the magnetic effect. When electric current passes through the filament of the bulb, it heats up and emits light. There is no significant magnetic effect involved in the operation of an electric bulb.

- **Option 2 (Electric Fuse):**
     - An electric fuse is a safety device that operates on the principle of the heating effect of electric current. It contains a thin wire that melts and breaks the circuit when excessive current flows through it, preventing damage to the circuit. The operation of a fuse is not related to the magnetic effect of electric current.

- **Option 4 (Electric Press):**
     - An electric press, such as an iron, also relies on the heating effect of electric current. It converts electrical energy into heat energy to press clothes. There is no use of the magnetic effect in its operation.

In conclusion, the electric bell is the only device among the options that utilizes the magnetic effect of electric current, making Option 3 the correct answer.