Current Electricity

To solve the problem, we need to identify the typical current at which an electrical fuse melts and breaks the circuit.

1. Understanding the Purpose of a Fuse:
A fuse is a safety device designed to protect electrical circuits from excessive current. It is made of a metal wire or strip that melts when too much current flows through it, thereby breaking the circuit and preventing damage or fire.

2. Typical Fuse Ratings:
For domestic and standard electrical appliances, fuses are typically rated around:

• 1 A to 15 A for small appliances
• Up to 20 A for larger devices or circuits

Values like 200 A or 2000 A are far beyond normal fuse ratings and are typically seen in industrial or special-purpose high-current systems, not in regular fuse applications.

Final Answer:
A fuse generally melts when the current exceeds 20 A (Option C).

To solve the problem, we need to understand the typical range of electrical resistance offered by the human body.

1. Understanding Human Body Resistance:
The resistance of the human body varies widely depending on factors like skin condition (wet or dry), the path of current through the body, and individual physiology.

2. General Range:
- For dry skin, the resistance can be very high, up to 5,00,000 ohms (500 kΩ).
- For wet skin, resistance can drop significantly, even below 1,000 ohms.
Hence, the full range typically lies between 100 Ω to 5,00,000 Ω.

Final Answer:
The correct answer is option (D): 100 Ω to 5,00,000 Ω.