17V:=192) P
B
Consider the adjacent circuit
A generator G (174, 19)
Resistors R32 &R= 60
R
Arheostat Rh of variable resistance
An unknown electne component D.
An unmeter A, of negligible intemal resistance
I When the theostat is set to a resistance Rh=39, the
R₂
current flows through Ri is I = 1A.
a) The animerer A, has the following ranges: 6A, 3A, 300mA and 30mA
1) Which range is the most convenient to measure I,? Justify
2) To which division, using the most convenient range, will the needle of the ammeter deviate
if ils dial contains ISO divisions?
b) Calculate the resistant of the resistor equivalent to R, and Rs.
© Calculate the equivalent resistance between A and C.
© Find Vas
RI
2) Calculate la and I
) Calculate Vw and Ven
II) In this part, we vary the resistance of the rheostat. I and Uen across the terminals of D vary according
to the following table.
VN (V) 2.4
(А)
0.1
3.6
0.4
4
0.5
0.2
0 3
a) Draw the characteristic curve CV en D of D.
b) Deduce the nature of D.
C) Determine the characteristics of D.​