70th BPSC Prelims Re-exam 2025
General Science Previous Year Questions (PYQs)
Explore 28 solved 70th BPSC Prelims Re-exam 2025 General Science questions with detailed step-by-step bilingual solutions, option analysis, and answer keys.
Actual site of dark reaction in photosynthesis inside cytoplast is
Detailed Explanation:
Dark reaction (Calvin cycle) occurs in the stroma of the chloroplast, the fluid-filled region surrounding the grana.
Granum (stacks of thylakoid membranes) and grana lamella (connections between grana) are sites of light reactions, not dark reactions.
A nail is nailed into the trunk of a tree at a point 1 m from the soil level. After 2 years the nail will
Detailed Explanation:
Trees grow in height from apical meristems (shoot and root tips), not by elongating the trunk itself.
The nail remains at 1 m height because secondary growth (cambium activity) only increases girth, not vertical position of existing trunk sections.
Reactance of a capacitor is
Detailed Explanation:
Capacitive reactance (Xc) is given by the formula Xc = 1/(2πfC), where f is frequency and C is capacitance.
Since f appears in the denominator, as frequency increases, reactance decreases — meaning Xc ∝ 1/f (inversely proportional to frequency).
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The Ishihara test is related with
Detailed Explanation:
The Ishihara test is a widely used medical screening tool designed to detect colour vision deficiency, specifically red-green colour blindness.
It consists of plates with coloured dots that form numbers or patterns visible only to individuals with normal colour vision; those with red-green deficiency fail to identify the hidden figures, making it the standard diagnostic method for colour blindness.
Buds are typically found
Detailed Explanation:
Plants have two main types of buds: apical buds (terminal buds) located at the tip of branches that enable vertical growth, and axillary buds (lateral buds) located at the base of leaves in the leaf axil that develop into side branches or flowers.
Therefore, buds are found at both locations – at the tip of branches and at the base of leaves.
Sour taste of vinegar is due to
Detailed Explanation:
The sour taste of vinegar is due to acetic acid (CH₃COOH), which is produced by fermentation of ethanol.
Tartaric acid is found in tamarind and grapes, lactic acid in sour milk and curd, and citric acid in citrus fruits — none of these is the acid in vinegar.
Standard electrode potential of three metals A, B and C are respectively 0.5 V, -3 V and -1.2 V. Reducing power of these metals would be
Detailed Explanation:
Reducing power is inversely related to standard electrode potential (E°) — the more negative the E°, the stronger the reducing agent.
Metal B (−3.0 V) has the most negative potential → highest reducing power. Metal C (−1.2 V) is moderately negative → intermediate reducing power. Metal A (+0.5 V) is positive → lowest reducing power. Order: B > C > A.
Steam methane reforming technique is used to obtain
Detailed Explanation:
Steam Methane Reforming (SMR) reacts natural gas (methane) with high-temperature steam to produce hydrogen and carbon dioxide (CO₂) as a by-product.
Since the process emits CO₂ without carbon capture, the hydrogen produced is classified as Grey Hydrogen. Brown Hydrogen comes from coal gasification, while Green Hydrogen is produced via water electrolysis using renewable energy with zero emissions.
Showing 21 to 28 of 28 questions
70th BPSC Prelims Re-exam 2025 - General Science Chapter-wise Distribution
Biology
11 Qs (39.3%)Physics
8 Qs (28.6%)Chemistry
6 Qs (21.4%)Science and Technology Developments
3 Qs (10.7%)70th BPSC Prelims Re-exam 2025 - General Science Questions FAQs
Q1 How many General Science questions were asked in 70th BPSC Prelims Re-exam 2025 2024?
Q2 What is the chapter-wise question distribution for General Science in 70th BPSC Prelims Re-exam 2025 2024?
- Biology: 11 questions (39.3%)
- Physics: 8 questions (28.6%)
- Chemistry: 6 questions (21.4%)
- Science and Technology Developments: 3 questions (10.7%)