BPSC CCE Prelims
General Science Previous Year Questions (PYQs)
Solved Previous Year Questions (PYQs) for General Science in BPSC CCE Prelims in English & Hindi Medium.
Chapter Breakdown: Scroll →
Which among the following is a positively charged particle emitted by a radioactive element?
Detailed Explanation:
Alpha particles (α) are positively charged particles emitted during radioactive decay, consisting of 2 protons + 2 neutrons (essentially a helium nucleus).
Beta rays (β) are negatively charged electrons, while cathode rays are also streams of electrons, both carrying negative charge.
Therefore, Option 3 (Alpha ray) is the correct answer.
Centripetal force is responsible to
Detailed Explanation:
Centripetal force is the net force directed towards the center of a circular path that keeps an object moving in circular motion.
Without centripetal force, an object would continue moving in a straight line due to inertia (Newton's first law), not along a curved path.
Examples: Tension in a string (whirling stone), gravitational force (planetary orbits), friction (car turning).
Which of the following energy changes involves frictional force?
Detailed Explanation:
✅ Option 1 – Correct: Kinetic energy to heat energy conversion involves frictional force. When objects move against each other (e.g., rubbing hands, braking vehicles), friction opposes motion and converts kinetic energy into heat energy.
❌ Option 2 – Incorrect: Potential energy to sound energy conversion (e.g., ringing bell, falling object hitting ground) does not require friction; it involves vibrations and mechanical energy transfer.
❌ Option 3 – Incorrect: Chemical energy to heat energy conversion (e.g., combustion, digestion) occurs through chemical reactions, not through frictional force.
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A bus is moving along a straight path and takes a sharp turn to the right side suddenly. The passengers sitting on the bus will
Detailed Explanation:
When a bus takes a sharp right turn, the passengers' bodies tend to continue moving in a straight line due to inertia of motion.
Since the bus turns right, the passengers experience a tendency to move in the original direction, causing them to bend towards the left side relative to the bus.
This is an application of Newton's First Law of Motion (law of inertia), which states that a body in motion continues in its state unless acted upon by an external force.
Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he/she is adjusting
Detailed Explanation:
✅ Statement 1 – Correct: Tuning a sitar before an orchestra involves adjusting the tension of the strings to match the frequency (pitch) with other instruments, ensuring all instruments play in harmony at the same musical scale.
❌ Statement 2 – Incorrect: Amplitude determines the loudness of sound, not the tuning; adjusting tension changes frequency/pitch, not amplitude.
❌ Statement 3 – Incorrect: Intensity (energy per unit area) is related to amplitude and distance, not directly adjusted through string tuning; tuning modifies frequency only.
A form of matter has no fixed shape but it has a fixed volume. An example of this form of matter is
Detailed Explanation:
Matter with no fixed shape but fixed volume is a liquid.
✅ Kerosene is a liquid – has fixed volume but takes the shape of its container.
❌ Carbon steel is a solid – has both fixed shape and fixed volume.
❌ Krypton is a noble gas – has neither fixed shape nor fixed volume.
Some metal oxides react with acid as well as a base to produce salt and water. They are known as amphoteric oxides. Examples of amphoteric oxides are
Detailed Explanation:
Amphoteric oxides react with both acids and bases to form salt and water.
✅ Al₂O₃ (Aluminium oxide) reacts with HCl to give AlCl₃ + H₂O and with NaOH to give NaAlO₂ + H₂O.
✅ ZnO (Zinc oxide) reacts with H₂SO₄ to give ZnSO₄ + H₂O and with NaOH to give Na₂ZnO₂ + H₂O.
❌ CuO (Copper oxide) is a basic oxide that reacts only with acids, not with bases.
Therefore, Option 2 (Al₂O₃ and ZnO) is the correct answer.
Acids react with metal carbonates to liberate ______ gas.
Detailed Explanation:
When acids react with metal carbonates, the general reaction is: Acid + Metal Carbonate → Salt + Water + CO₂.
For example, HCl + CaCO₃ → CaCl₂ + H₂O + CO₂, producing carbon dioxide gas (CO₂) which is observed as effervescence (bubbles).
Which acid is described as HOOCCOOH?
Detailed Explanation:
HOOCCOOH is the chemical formula for Oxalic acid, a dicarboxylic acid with two carboxyl groups (-COOH).
Carbonic acid is H₂CO₃, Acetic acid is CH₃COOH, making Option 2 the only correct answer.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. Which of them will turn red litmus to blue?
Detailed Explanation:
Red litmus paper turns blue only in the presence of a basic (alkaline) solution.
Distilled water is neutral (pH 7) and does not change litmus colour; acidic solutions turn blue litmus red, not the reverse; only bases have the chemical property to convert red litmus to blue.
The odour of acetic acid resembles that of
Detailed Explanation:
Acetic acid is the main component of vinegar, giving it its characteristic pungent, sour smell.
Vinegar typically contains 4-8% acetic acid by volume, which is why the odour of pure acetic acid closely resembles that of vinegar.
Why does dry HCI gas not change the colour of dry litmus paper?
Detailed Explanation:
Dry HCl gas does not ionize to produce H₃O⁺ (hydronium) ions because ionization requires the presence of water molecules.
Litmus paper changes colour only when H₃O⁺ ions are present in solution; dry HCl remains molecular (HCl) and cannot act as an acid without water to donate protons to.
Detect the odd one.
Detailed Explanation:
✅ Option 1 – Ripening of fruit: This is an irreversible change (fruit cannot be un-ripened).
✅ Option 2 – Setting of cement: This is an irreversible change (cement cannot return to powder form once set).
✅ Option 3 – Burning of coal: This is an irreversible change (coal once burned cannot be recovered).
All three options represent irreversible changes, so none of them is the odd one out. Hence, Option 5 (None of the above) is correct.
Which of the following statements about diamond and graphite is true?
Detailed Explanation:
❌ Statement 1 – Incorrect: Diamond is an electrical insulator (no free electrons), while graphite is a good electrical conductor (has delocalized electrons in layers).
❌ Statement 2 – Incorrect: Diamond has a tetrahedral crystal structure (each carbon bonded to 4 others in 3D), while graphite has a hexagonal layered structure (each carbon bonded to 3 others in 2D layers).
❌ Statement 3 – Incorrect: Diamond is the hardest natural substance (Mohs scale 10), while graphite is soft and slippery (Mohs scale 1-2) due to weak van der Waals forces between layers.
Both are allotropes of carbon with vastly different physical properties due to different atomic arrangements.
The stomata open or close due to change in the
Detailed Explanation:
Stomatal opening and closing is regulated by the turgor pressure in guard cells.
When guard cells absorb water, they become turgid and the stomata open; when they lose water, they become flaccid and the stomata close.
✅ Option 3 – Correct: The amount of water in cells directly controls the opening and closing of stomata through changes in turgor pressure.
❌ Option 1 – Incorrect: Position of nucleus does not affect stomatal movement.
❌ Option 2 – Incorrect: While proteins are involved in water transport mechanisms, the immediate cause is water content, not protein composition change.