WHATSAPP Welcome to Edugrown – Your Learning Partner
🛒
Previous Year Questions

PYQ Bank & Paper Generator

Board, class, subject, chapter, year-wise PYQ. Practice effectively and ace your board exams.

9,374 Questions
CBSE
#1 Class 12 Physics Semiconductor 2020 Mcq 1M
Assuming the p-n junction diode shown is ideal, if the circuit has a battery of 2 V and a resistor of 100 $\Omega$ in series with the forward-biased diode, the current through the diode is
A. 0.02 A
B. 2:00 AM
C. 0.2 A
D. 20 A
👁 View Answer
👍 3 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#2 Class 12 Physics Semiconductor 2021 Mcq 1M
In comparison to a half-wave rectifier, the full-wave rectifier gives lower
A. efficiency
B. average current
C. average output voltage
D. none of these
👁 View Answer
👍 2 👎 3
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#3 Class 12 Physics Semiconductor 2020 Mcq 1M
When the p-end of a p-n junction is connected to the negative terminal and the n-end to the positive terminal of the battery, the p-n junction behaves like a/an
A. insulator
B. conductor
C. semiconductor
D. superconductor
👁 View Answer
👍 2 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#4 Class 12 Physics Semiconductor 2021 Mcq 1M
At 0 K temperature, a p-type semiconductor
A. does not have any charge carrier
B. has few holes and few free electrons
C. has few holes but no free electron
D. has equal number of holes and free electrons
👁 View Answer
👍 1 👎 1
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#5 Class 12 Physics Semiconductor 2019 Mcq 1M
When the conductivity of a semiconductor is only due to the breaking of covalent bonds, the semiconductor is called
A. extrinsic
B. intrinsic
C. n-type
D. p-type
👁 View Answer
👍 2 👎 1
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#6 Class 12 Physics Semiconductor 2018 Mcq 1M
A pure semiconductor behaves slightly as a conductor at
A. low temperature
B. high temperature
C. room temperature
D. both (a) and (b)
👁 View Answer
👍 1 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#7 Class 12 Physics Semiconductor 2020 Mcq 1M
With the increase of temperature, the width of the forbidden gap in a semiconductor
A. decreases
B. increases
C. remains same
D. becomes zero
👁 View Answer
👍 2 👎 3
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#8 Class 12 Physics Semiconductor 2019 Mcq 1M
The impurity atom that should be added to Germanium to make it an n-type semiconductor is
A. iodine
B. indium
C. arsenic
D. aluminium
👁 View Answer
👍 1 👎 1
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#9 Class 12 Physics Semiconductor 2020 Mcq 1M
The state of energy of the valence electrons when the temperature is raised or when an electric field is applied is called
A. valence band
B. conduction band
C. forbidden band
D. none of these
👁 View Answer
👍 3 👎 3
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#10 Class 12 Physics Semiconductor 2019 Mcq 1M
The majority current-carrier in a p-type semiconductor is
A. electron
B. hole
C. photon
D. proton
👁 View Answer
👍 2 👎 3
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#11 Class 12 Physics Semiconductor 2018 Mcq 1M
For n-type Germanium, the impurity doped in Germanium is
A. Trivalent
B. Tetravalent
C. Pentavalent
D. None of these
👁 View Answer
👍 2 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#12 Class 12 Physics Semiconductor 2019 Mcq 1M
A semiconductor is cooled from $T_1$ K to $T_2$ K. Its resistance will
A. increase
B. decrease
C. remain constant
D. first decrease then increase
👁 View Answer
👍 1 👎 1
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#13 Class 12 Physics Semiconductor 2020 Mcq 1M
The formation of depletion region in a p-n junction diode is due to
A. movement of dopant atoms
B. diffusion of both electrons and holes
C. drift of electrons only
D. drift of holes only
👁 View Answer
👍 2 👎 1
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#14 Class 12 Physics Semiconductor 2021 Short 2M
In an extrinsic semiconductor, the number density of holes is $4 \times 10^{20}$ m$^{-3}$. If the number density of intrinsic carriers is $1.2 \times 10^{45}$ m$^{-3}$, find the number density of electrons in it.
👁 View Answer
👍 1 👎 1
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#15 Class 12 Physics Nuclei 2022 Short 2M
What is the nuclear radius of $^{125}$Fe, if that of $^{27}$Al is 3.6 fermi?
👁 View Answer
👍 1 👎 1
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#16 Class 12 Physics Nuclei 2023 Short 5M
A coin has a mass of 3.0 g and is entirely made of $^{63}_{29}$Cu atoms (mass 62.92960 u). Calculate the nuclear energy required to separate all neutrons and protons from each other. Given: $m_p = 1.007825$ u, $m_n = ...
👁 View Answer
👍 2 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#17 Class 12 Physics Nuclei 2022 Short 2M
Binding energy per nucleon vs mass number curve for nuclei is shown in the figure. W, X, Y and Z are four nuclei indicated on the curve. Identify which nucleus is most likely to undergo: (i) Nuclear Fission, (ii) Nucl...
👁 View Answer
👍 3 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#18 Class 12 Physics Nuclei 2025 Short 3M
A fast-moving neutron collides with the nucleus of Plutonium ($^{239}$Pu), producing Xenon ($^{134}$Xe) and Zirconium ($^{103}$Zr) along with neutrons. (I) Write the nuclear fission reaction. (II) Find the number of n...
👁 View Answer
👍 3 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#19 Class 12 Physics Nuclei 2022 Long 5M
Give reasons for: (a) Lighter elements are better moderators for a nuclear reactor than heavier elements. (b) In a natural uranium reactor, heavy water is preferred over ordinary water as moderator. (c) Cadmium rods a...
👁 View Answer
👍 2 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
CBSE
#20 Class 12 Physics Nuclei 2021 Short 3M
Explain giving necessary reactions how energy is released during: (i) nuclear fission, (ii) nuclear fusion.
👁 View Answer
👍 2 👎 2
✅ Verified by Super Admin
Rate: ★ ★ ★ ★ ★
Advertisement

🔔 Email Updates Lein

Naya content aate hi email par pata chal jayega. Sirf wahi sections chunein jo chahiye.

🔒 Content copy nahi kar sakte