SPSC EVERYDAY SCIENCE 25 YEARS PAST PAPERS
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چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
نیوٹن ______ پر اپنی تحقیق کے لئے جانا جاتا ہے؟
Theory of population
Atomic structure
Laws of gravitation
None of these
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Explanation
Isaac Newton formulated the Law of Universal Gravitation . This stating that every mass attracts every other mass with a force proportional to their masses and inversely proportional to the square of the distance between them. His work in classical mechanics also led to the development of Newton's Three Laws of Motion.
شے کے مقابلے میں، عینک کے ذریعہ تشکیل دی گئی اصلی تصاویر ہمیشہ _____ ہوتی ہیں؟
Inverted
Larger
Smaller
None of these
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Explanation
Real images formed by a convex lens (converging lens) are always inverted because light rays actually converge at a point. These images can be projected on a screen , unlike virtual images , which are always upright .
کی عمر تلاش کرنے کے لئے ریڈیو کاربن ڈیٹنگ کا استعمال کیا جاتا ہے؟ _____
Plants
Rocks
Fossils
None of these
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Explanation
Carbon dating is used to estimate the age of fossils. Those that are less than 60,000 years old. It is composed of organic materials like wood or leather.
گریفائٹ جوہری ری ایکٹرز _____ میں استعمال ہوتا ہے؟
As a fuel
As a lubricant
For reducing the velocity of neutrons
None of these
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Explanation
Graphite is used in nuclear reactors as a neutron moderator .
It slows down high-energy neutrons to thermal energies to maintain the chain reaction efficiently.
3.33 m
3.33 mn
3.33 mm
None of these
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Explanation
Using the formula: λ = c / f (where λ = wavelength, c = speed of light, and f = frequency)
λ = (3 × 10^8 m/s) / (90 × 10^6 Hz) ≈ 3.33 m .
مندرجہ ذیل میں سے کس میں سب سے بڑی توانائی ہے؟
A photon of red light
A photon of blue light
A photon of violet light
None of these
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Explanation
Energy of a photon is given by E = hν , where ν (frequency) is directly proportional to energy. Violet light has the highest frequency.
373/273
273/373
100/0
None of these
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Explanation
According to Charles' Law , at constant pressure, the volume of a gas is directly proportional to its temperature in Kelvin. The temperature must be converted to Kelvin , so the volume correction factor is 373 273 frac{373}{273} , corresponding to the temperatures 100°C and 0°C .
3.5 kJ
3550 kJ
355 kJ
None of these
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Explanation
To boil 1 liter of water from 15°C to 100°C, the energy required is:
Q = mcΔT
= 1 kg × 4.18 kJ/kg°C × (100°C - 15°C)
= 1 × 4.18 × 85
= 355 kJ
Infrared
Visible
Ultraviolet
None of these
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Explanation
Ultraviolet (UV) light ranges from 10 nm to 400 nm , and 245 nm falls within this range. It is shorter than visible light but longer than X-rays.
ایک الیکٹران کی حرکیاتی توانائی جو دھات کی سطح سے نکالی گئی ہے جو مونوکرومیٹک تابکاری کے سامنے ہے _____ پر منحصر ہے؟
Wavelength of the light used
Intensity of the light used
Frequency of the light used
None of these
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Explanation
According to Einstein's photoelectric equation , the kinetic energy (K) of an ejected electron depends on the frequency (f) of the incident light :
K = hf - φ
where h is Planck's constant and φ is the work function of the metal.
