5. Normal functioning of a lamp Official 2018 - A series circuit is composed of a generator (G) that maintains across its terminals a constant voltage
0-24 V, an ammeter (A) of negligible resistance, a resistor (D) of resistance R, and a lamp (L)
considered as a resistor and carrying the indications (9W; 18V). In this circuit, (L) is functioning normally.
1. Draw a diagram of the above circuit.
2. What does each of the indications carries by (L) represent?
3. Show that the current through (L) is I 0.5A.
4. Deduce the value of the resistance R of (L).
5. 5.1. Calculate the voltage across (D).
5.2. Deduce the value of R.
6. We replace (D) by a connection wire.
6.1. What is the new voltage across (L)?
6.2. (L) may bum out. Why?
6.3. What was then the role of (D)?