Physics 5054 · O Level · Electrical safety

Electrical safety — practice question

The manufacturer of an electrical heater says that no more than one heater should be linked to the mains wiring through a single fuse. With just one heater in the circuit, the current is $9\,\text{A}$. The fuse rating is $10\,\text{A}$. Even though this warning is given, a second identical heater is connected, as shown. When the switch is closed, the fuse blows. The fuse is then changed for a $20\,\text{A}$ fuse. What occurs when the switch is closed?

  • AEach heater only receives half the correct current.
  • BEach heater receives twice the correct current.
  • CThe circuit wiring connecting the heaters to the mains may overheat.
  • DThe fuse melts when the heaters are switched on.

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