NEET 2019 Model Question Paper 1

Voltage drop across diode (VD)=0.5V; Maximum power rating of diode (P) = 100 m W
And source voltage (Vs)=1.5V
The resistance of diode (RD) =

VD2

P

=

(0.5)2

100×10−3

=2.5Ω
And current in diode (ID)=

VD

RD

=

0.5

2.5

=0.2Ω
Therefore total resistance in circuit (R) =

Vs

ID

=

1.5

0.2

=7.5Ω
And the value of the series resistor
= Total resistance of the circuit – Resistance of diode
=7.5−2.5=5Ω