SPSC LECTURER PHYSICS PAST PAPER 20-01-2025
Lecturer Physics 5 years Past Papers Click Here
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چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
پیکنگ کثافت _______ کے لیے زیادہ سے زیادہ ہے؟
Simple cubic lattice
Body centered lattice
Face centered cubic lattice
None of these
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Explanation
The packing density (atomic packing factor) is highest for the face-centered cubic (FCC) lattice at 74%. FCC structure has closely packed atoms compared to simple cubic (52%) and body-centered cubic (68%).
توانائی کی قیمت جس تک تمام توانائی کی حالتیں مطلق صفر پر بھری ہوئی ہیں اور جس سے اوپر تمام ریاستیں خالی ہیں اسے _____ کہا جاتا ہے؟
Maximum energy
Fermi energy
Ground state energy
None of these
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Explanation
The Fermi energy is the highest energy level that electrons occupy at absolute zero temperature.
Above this energy, states are empty , and below it, they are filled .
5/4 MR^2
3/2 MR^2
3/2 MR^2
None of these
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Explanation
Using the Parallel Axis Theorem:
I = I_CM + Md^2
where I_CM = MR^2/2 and d = R (radius)
I = MR^2/2 + MR^2
= 3/2 MR^2
24 kg wt
16 kg wt
12 kg wt
None of these
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Explanation
The frequency of a stretched string is proportional to the square root of the tension. To produce an octave (double frequency) , the tension must increase fourfold. Since the original tension is from 4 kg , the required tension is 4 × 4 = 16 kg wt .
پی قسم کے سیمی کنڈکٹر جرمینیم کرسٹل کو حاصل کرنے کے لیے، اسے غیر ملکی ایٹموں کے ساتھ ڈوپ کیا جانا چاہیے جن کی ویلینسی _____ ہے؟
4
2
3
None of these
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Explanation
P-type semiconductors are created by doping with trivalent atoms (valency 3) like boron or indium . It create " holes " by accepting electrons. These holes act as charge carriers , giving the semiconductor its p-type behavior.
مندرجہ ذیل میں سے کون سا جوہری ٹھوس کے بارے میں غلط بیان ہے؟
All atomic solids have high melting points
Atomic solids are a type of crystalline solids
The composite unit of atomic solids are atoms
Atomic solids are held together by dispersion forces, metallic bonds, and covalent bond
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Explanation
Atomic solids can have low, moderate, or high melting points depending on the type of bonding (e.g., noble gases with weak dispersion forces have low melting points ). Atomic solids are crystalline solids, and their composite units are atoms arranged in a lattice structure.
مندرجہ ذیل میں سے کون سا جوہری ایندھن کی کلڈنگ مواد کے طور پر استعمال نہیں ہوتا ہے؟
Iron
Cadmium
Ceramics
None of these
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Explanation
Nuclear fuel cladding materials should have low neutron absorption and high melting points.
Cadmium has a high neutron absorption cross-section, making it unsuitable for cladding.
Spherical shell
Sheet of change
Line change
None of these
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Explanation
The variation of Electric field (E) with distance (r) is observed as 1/r² for a spherical shell.
This is consistent with Gauss's Law for a spherical shell.
Token
Salute
Gesture
None of these
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Explanation
The phrase " held up his first " indicates a physical action.
The word " defiant " suggests a bold or challenging attitude.
ایک ہی تصادم میں بیٹا ذرہ _____؟
Loses no energy at all
Loses most of its energy
Loses a small fraction of its energy
None of these
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Explanation
Beta particles lose only a small fraction of their energy in a single encounter with matter. They can continue to travel through materials , gradually losing energy over multiple interactions.
