11. (JEE
Main
2021
(Online)
1st
September
Evening
Shift)
In
the
given
figure,
each
diode
has
a
forward
bias
resistance
of
30
and
infinite
resistance
in
reverse
bias.
The
current
I1
will
be
:
A.
3.75
A
B.
2.35
A
C.
2
A
D.
2.73
A
The Correct Answer is Option (C)
As
per
diagram,
Diode
D1
&
D2
are
in
forward
bias
i.e.
R
=
30
whereas
diode
D3
is
in
reverse
bias
i.e.
R
=
infinite
Equivalent
circuit
will
be
Applying
KVL
starting
from
point
A
30
I1
+
200
=
0
I1
=
2
Option
(c)
12. (JEE
Main
2021
(Online)
31st
August
Morning
Shift)
Choose
the
correct
waveform
that
can
represent
the
voltage
across
R
of
the
following
circuit,
assuming
the
diode
is
ideal
one
:
A.
B.
C.
D.
The Correct Answer is Option (D)
When
Vi
>
3
volt,
VR
>
0
Because
diode
will
be
in
forward
biased
state
When
Vi
3
volt
;
VR
=
0
Because
diode
will
be
in
reverse
biased
state.
13. (JEE
Main
2021
(Online)
25th
February
Morning
Shift)
A
5V
battery
is
connected
across
the
points
X
and
Y.
Assume
D1
and
D2
to
be
normal
silicon
diodes.
Find
the
current
supplied
by
the
battery
if
the
+ve
terminal
of
the
battery
is
connected
to
point
X.
A.
0.5
A
B.
1.5
A
C.
0.43
A
D.
0.86
A
The Correct Answer is Option (C)
Since
silicon
diode
is
used
so
0.7
Volt
is
drop
across
it,
only
D1
will
conduct.
So
current
through
cell,
I
=
=
0.43
A
14. (JEE
Main
2020
(Online)
5th
September
Evening
Slot)
Two
Zener
diodes
(A
and
B)
having
breakdown
voltages
of
6
V
and
4
V
respectively,
are
connected
as
shown
in
the
circuit
below.
The
output
voltage
V0
variation
with
input
voltage
linearly
increasing
with
time,
is
given
by
:
(Vinput
=
0
V
at
t
=
0)
(figures
are
qualitative)
A.
B.
C.
D.
The Correct Answer is Option (D)
Till
input
voltage
reaches
4V,
both
diode
will
stay
deactvated
so
output
voltage
will
be
same
as
input
voltage.
When
input
voltage
reach
4V,
then
4V
diode
will
get
activated
and
it
will
transfer
only
4V
to
the
output
but
as
a
rasistance
is
present
in
series
with
the
4V
diode
so
some
voltage
drop
will
happen
across
the
resistor.
So
output
voltage(Vo)
will
be
=
4V
+
voltage
drop.
When
input
voltage
reach
6V,
then
6V
diode
will
get
activated
and
it
will
transfer
only
6V
to
the
output
no
matter
how
much
input
voltage
become.
15. (JEE
Main
2020
(Online)
3rd
September
Morning
Slot)
When
a
diode
is
forward
biased,
it
has
a
voltage
drop
of
0.5
V.
The
safe
limit
of
current
through
the
diode
is
10
mA.
If
a
battery
of
emf
1.5
V
is
used
in
the
circuit,
the
value
of
minimum
resistance
to
be
connected
in
series
with
the
diode
so
that
the
current
does
not
exceed
the
safe
limit
is