Step 1: What is Spot Welding? Spot welding is a type of resistance welding used to join two or more metal sheets together by applying pressure and electrical current. It is commonly used in automobile, aerospace, and sheet metal industries.
Step 2: Why Thin Metal Sheets? - Spot welding works best for thin metal sheets (typically 0.5 mm to 3 mm thick).
- It creates localized heat at the weld points using high current, causing the sheets to fuse.
Step 3: Evaluating options:
- (A) Correct: Spot welding is primarily used for thin metal sheets.
- (B) Incorrect: Thick metal rods require arc welding or friction welding.
- (C) Incorrect: Thick square sections need MIG/TIG welding for strong joints.
- (D) Incorrect: Rough or irregular surfaces are difficult to weld using spot welding.
The motion of electrons in a CRT is due to:
The direction of current flow in the circuit is such that the induced magnetic field produced by the induced current will oppose the original magnetic field. This is:
The electromagnetic wave propagates in free space with a speed of: