SPSC PHYSICS 25 YEARS PAST PAPERS
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چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
گاؤس ڈائیورجنس تھیوریم ______ کو تبدیل کرتا ہے؟
Surface to line integral
Surface to volume integral
Line to volume integral
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
The Gauss divergence theorem , also known as the divergence theorem, converts:
Volume integral to Surface integral
It states that the volume integral of the divergence of a vector field over a region is equal to the surface integral of the vector field over the boundary of that region.
Mathematically, it is expressed as:
∫∫∫_V (∇⋅F) dV = ∫∫_S F⋅dS
ایک جہتی آسکیلیٹرز کی اوسط توانائی کے لئے کلاسیکی اظہار ہے؟
(3/2 KBT)
(1/2 KBT)
(KBT/2 + KBT/2)
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
The classical expression for the mean energy of a one-dimensional oscillator is: (1/2 KBT) + (1/2 KBT)
= KBT
0.048
0.768
0.003
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
The average translational kinetic energy of a molecule is given by:
(3/2)kT = (3/2) × (1.38 × 10^-23 J/K) × T
Since the temperature is the same for both O2 and N2 molecules , the average translational kinetic energy will be the same:
0.048 eV = (3/2)kT
The mass of the molecule does not affect the average translational kinetic energy .
Therefore, the translational kinetic energy of N2 molecules at the same temperature is also:
0.048 eV
ویکیوم یا خالی جگہ ، کون سے مشاہدات کیے جاتے ہیں؟
p = 0, J = 0
p = po, J = 0
p = 0, J = J
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
In a vacuum or free space, there are no particles or matter, so:
Pressure (p) is zero . Current density (J) is also zero , since there are no charged particles to carry current. Therefore, the correct observation is p = 0, J = 0.
0.26 m
0.36 m
0.83
None of these
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Explanation
1/f = 1/v - 1/u
2.5 = 1/0.75 - 1/u
u = -0.26 m
So, the new near point is indeed:
0.26 m
کسی سیارے کے بڑے پیمانے پر اور قطر زمین سے دوگنا ہوتا ہے۔ پینڈولم سیارے کے دوچار ہونے کی مدت ہوگی (اگر یہ زمین پر دوسرا لاکٹ ہے)؟
2√2 seconds
1√2 seconds
1/2 second
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
The formula for the period of a pendulum is T = 2π√(l/g) , where l is the length of the pendulum and g is the acceleration due to gravity. Since the mass and diameter are doubled , the acceleration due to gravity (g) on the planet will be half that of Earth. Therefore, the new period of oscillation will be √2 times the period on Earth, meaning if it was a second's pendulum on Earth, it will be 2√2 seconds on the planet.
275K
325K
250K
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
Initial efficiency (η) = 40% = 0.4
Sink temperature (Tc) = 300 K
Initial source temperature (Th) = 300 / (1 - 0.4) = 500 K
New efficiency (η_new) = 0.4 + 0.5(0.4) = 0.6
New source temperature (Th_new) = 300 / (1 - 0.6) = 750 K
Increase in temperature = Th_new - Th = 750 - 500 = 250 K
ایک ڈوپول میں ، گاؤس تھیوریم کی قیمت _____ ہوگی؟
2
1
0
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
Gauss's Theorem (Gauss's Law) : States that the total electric flux through a closed surface is proportional to the enclosed charge. Dipole Net Charge : A dipole consists of equal and opposite charges (+q and -q). So the net charge enclosed by any Gaussian surface around it is zero . This making the Gauss theorem value 0 .
50°
30°
40°
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
Since μ = 1/√3, we can use the fact that μ = tan(θ) when the block just slides down the inclined plane.
μ = 1/√3 = tan(θ)
θ = arctan(1/√3)
θ = 30°
2.05 MeV
4.1 MeV
1.02 MeV
None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
Given:
Energy of photon (E) = 4.1 MeV
The total energy available for the electron and positron is:
E - 2 × 0.511 MeV = 4.1 MeV - 1.022 MeV = 3.078 MeV
Since the electron and positron share the energy equally, the kinetic energy of the electron is:
3.078 MeV / 2 = 1.539 MeV
Adding the rest mass energy of the electron (0.511 MeV), we get:
Energy of electron = 1.539 MeV + 0.511 MeV = 2.05 MeV
