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11. (JEE Main 2021 (Online) 1st September Evening Shift)

In the given figure, each diode has a forward bias resistance of 30 Ω and infinite resistance in reverse bias. The current I1 will be :

JEE Main 2021 (Online) 1st September Evening Shift Physics - Semiconductor Question 57 English

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 Ω whereas diode D3 is in reverse bias i.e. R = infinite Equivalent circuit will be

Applying KVL starting from point A

JEE Main 2021 (Online) 1st September Evening Shift Physics - Semiconductor Question 57 English Explanation
( I 1 2 ) × 30 ( I 1 2 ) × 130 I 1 × 20 + 200 = 0 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 :

JEE Main 2021 (Online) 31st August Morning Shift Physics - Semiconductor Question 60 English

A. JEE Main 2021 (Online) 31st August Morning Shift Physics - Semiconductor Question 60 English Option 1

B. JEE Main 2021 (Online) 31st August Morning Shift Physics - Semiconductor Question 60 English Option 2

C. JEE Main 2021 (Online) 31st August Morning Shift Physics - Semiconductor Question 60 English Option 3

D. JEE Main 2021 (Online) 31st August Morning Shift Physics - Semiconductor Question 60 English Option 4

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.

JEE Main 2021 (Online) 25th February Morning Shift Physics - Semiconductor Question 94 English

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 = 5 0.7 10 = 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)

JEE Main 2020 (Online) 5th September Evening Slot Physics - Semiconductor Question 102 English

A. JEE Main 2020 (Online) 5th September Evening Slot Physics - Semiconductor Question 102 English Option 1

B. JEE Main 2020 (Online) 5th September Evening Slot Physics - Semiconductor Question 102 English Option 2

C. JEE Main 2020 (Online) 5th September Evening Slot Physics - Semiconductor Question 102 English Option 3

D. JEE Main 2020 (Online) 5th September Evening Slot Physics - Semiconductor Question 102 English Option 4

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

A. 50 Ω

B. 200 Ω

C. 300 Ω

D. 100 Ω

The Correct Answer is Option (D)

JEE Main 2020 (Online) 3rd September Morning Slot Physics - Semiconductor Question 107 English Explanation

1.5 – 0.5 – R × 10–2 = 0

R = 100 Ω