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Physics · Practical apparatus

Bulb branches and fuse model

Practical apparatus

Each branch switch controls its own parallel bulb, while the common fuse controls both. Current demand is the sum of branch currents. Changing voltage changes power through the fixed hot-resistance guide.

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Bulb branches and fuse model

இணை கிளைகளின் சுவிட்சுகள் தனித்தனியாகப் பல்புகளை இயக்கும். பொது உருகி திறந்தால் இரண்டும் அணையும்.

Key notes, relationships and model limits

Key relationship

Bulb R=230²/Prated; Pactual=V²/R; parallel currents add; ideal fuse opens if Irequested>Ilimit.

Practical tip

Each branch switch controls its own parallel bulb, while the common fuse controls both. Current demand is the sum of branch currents. Changing voltage changes power through the fixed hot-resistance guide.

Common trap

This fixed-resistance bulb and instantaneous fuse are explicit simplifications.

Model limits

Virtual household topology; bulbs modelled as fixed resistors at rated hot resistance. Ideal instantaneous fuse, no thermal time dependence. No physical assembly is implied.

What you will learn

Read parallel branch power and common fuse behavior.

Try the experiment

Try both scenarios, change one control, and predict the result before checking the graph and readouts.

Think of it this way

Change one input while keeping the others fixed, as you would in a controlled experiment.

Worked example

At230 V,60 W+100 W demand160/230≈0.696 A.

Why this matters

The model connects bulb branches and fuse model with an observable reading. Check the equation and assumptions before applying it.

Before you start

SI units · algebra · graph reading

Check your understanding

Opening one branch switch in a parallel circuit leaves the other branch?

Read the explanation

Parallel branches retain independent source connections.

Course connection: Virtual apparatus preparation. Check exact board/exam membership in the syllabus sources. Physical practical work remains necessary.