JST 5 YEARS PAST PAPERS
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چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
مقررہ کمیت والی گیس کے لیے جب دباؤ مستقل ہو تو اس کا حجم مطلق درجہ حرارت کے متناسب ہوتا ہے۔ یہ کس قانون کو ظاہر کرتا ہے؟
- Avogadro's law
- Boyle's law
- Charles law
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- When pressure is constant, the volume of a gas changes directly with temperature (in Kelvin).
- As temperature increases, gas particles move faster and occupy more space.
- This relationship is used to describe gas expansion.
- It applies only at constant pressure conditions.
- This is known as Charles’s Law.
Last verified on 12-04-2026
ایٹم کے نیوکلئس کو چھوٹے یونٹوں میں تقسیم کرنے کا عمل کیا ہے؟
- Fusion
- Dillusion
- Fission
- Diffusion
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Fission is the process of splitting an atomic nucleus into smaller nuclei, releasing a large amount of energy.
- It is used in nuclear power plants and atomic bombs.
Last verified on 12-04-2026
اگر کسی موج کی فریکوئنسی کو دوگنا کر دیا جائے (رفتار مستقل ہو)، تو اس کی طولِ موج کیا ہو گی؟
- Zero
- Unchanged
- Halved
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Wave speed is given by v = fλ.
- If speed remains constant, frequency and wavelength are inversely related.
- So, when frequency increases, wavelength decreases.
- If frequency is doubled, wavelength becomes half.
- This is a basic wave relation in physics.
Last verified on 12-04-2026
جسمانی مقدار ورک (کام) کی ڈائمینشنس کیا ہیں؟
- ML²T⁻²
- M²LT⁻²
- ML²T²
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Work is defined as force × displacement.
- Force has dimensions MLT⁻².
- Displacement has dimension 𝐿.
- So, work = MLT⁻² × 𝐿 = ML²T⁻².
Last verified on 12-04-2026
ہیبر پروسیس کے ذریعے امونیا کی تیاری کے بارے میں کون سا بیان درست ہے؟
- The reactants are both obtained from the air
- The reactants and product are elements
- The reactants and product are gases
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Haber process is used to manufacture ammonia from nitrogen and hydrogen.
- Nitrogen is obtained from air, but hydrogen is usually obtained from natural gas or water, not both from air.
- Ammonia is formed as a compound.
- The reaction involves gases under high pressure and temperature.
- Therefore, the correct statement is about physical state of reactants and product.
Last verified on 12-04-2026
- Burette, Pipette, Thermometer
- Balance, Measuring Cylinder, Thermometer
- Balance, Pipette, Thermometer
- Balance, Pipette, Stopwatch
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- To obtain accurate results, precise measurement of mass and volume is essential.
- A balance is used to measure 2.5 g sodium carbonate accurately.
- A pipette measures 25.0 cm³ acid more accurately than a measuring cylinder.
- A thermometer is needed to record temperature change.
- Therefore, these three give the most accurate results.
Last verified on 12-04-2026
اگر میگنیشیم کی ربن کی بجائے پاؤڈر استعمال کیا جائے تو ہائیڈروکلورک ایسڈ کے ساتھ ردِعمل کی رفتار پر کیا اثر ہوگا؟
- The rate would decrease
- No effect on the rate
- The rate would increase
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Powdered magnesium has a much larger surface area compared to magnesium ribbon.
- A greater surface area allows more collisions between magnesium and hydrochloric acid particles.
- This increases the frequency of successful collisions.
- Therefore, the reaction rate increases.
- So, powdered magnesium reacts faster than ribbon.
Last verified on 12-04-2026
برقی منفیّت میں اضافہ کب ہوتا ہے؟
- Does not change from top to bottom in group
- Left to right in a period
- Increases with the gain of electrons
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Electronegativity is the ability of an atom to attract electrons in a bond.
- It increases across a period from left to right due to increasing nuclear charge.
- It decreases down a group because atomic size increases.
- Therefore, the correct trend is left to right in a period.
Last verified on 12-04-2026
میگنیشیم، فاسفورس اور کلورین متواتر جدول کے ایک ہی دور کے عناصر ہیں۔ ان کے آکسائیڈز کی نوعیت کیا ہوگی؟
- Magnesium → Acidic, Phosphorus → Basic, Chlorine → Basic
- Magnesium → Acidic, Phosphorus → Acidic, Chlorine → Basic
- Magnesium → Basic, Phosphorus → Basic, Chlorine → Acidic
- Magnesium → Basic, Phosphorus → Acidic, Chlorine → Acidic
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Across a period, metallic character decreases from left to right.
- Magnesium is a metal, so it forms a basic oxide.
- Phosphorus and chlorine are non-metals, so they form acidic oxides.
- Therefore, Mg → basic, P → acidic, Cl → acidic oxides.
Last verified on 12-04-2026
مندرجہ ذیل میں سے کون سا/سے بیان درست ہیں؟
- Only 1
- Only 1 and 2
- Only 2 and 3
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
- Elements in the same group have similar chemical properties because they have the same number of valence electrons, not total electrons.
- They show similar reactions due to similar outer shell configuration.
- However, they differ in atomic (proton) number and mass number.
- Therefore, statement 2 and 3 are correct.
Last verified on 12-04-2026
