68th BPSC Prelims 2023 Question Paper
Explore the complete solved question paper for 68th BPSC Prelims 2023 featuring 150 solved questions with bilingual (English & Hindi) explanations, official answer key, and subject weightage breakdown.
A goalkeeper in a game of football pulls his hands backwards after holding the ball shot at the goal. This enables the goalkeeper to
Detailed Explanation:
✅ Statement 1 – Correct: By pulling hands backwards, the goalkeeper increases the time duration over which the ball's momentum changes to zero. Since Force = rate of change of momentum (F = Δp/Δt), increasing Δt decreases the force experienced, thereby decreasing the rate of change of momentum.
❌ Statement 2 – Incorrect: Pulling hands backwards reduces the force exerted on the ball, not increases it, by extending the time of contact.
❌ Statement 3 – Incorrect: The action decreases the force exerted by the ball on hands by increasing the stopping time, as per Newton's Third Law.
Ball bearings are used to convert static friction into
Detailed Explanation:
Ball bearings contain small spherical balls that convert static friction (friction between surfaces at rest) into rolling friction.
Rolling friction is significantly lower than sliding friction, allowing wheels, gears, and machinery to move smoothly and efficiently with reduced energy loss.
Which of the following photoelectric devices is most suitable for digital applications?
Detailed Explanation:
❌ The given answer is INCORRECT.
A photodiode is most suitable for digital applications because it operates in reverse bias mode and produces fast switching responses (ON/OFF states) essential for digital circuits, making it ideal for optical communication, sensors, and logic circuits.
A photovoltaic cell (solar cell) generates continuous electrical power from light and is designed for power generation applications, not digital switching or signal processing.
Photoemitters emit electrons when exposed to light but are used in specialized devices like photomultiplier tubes, not standard digital applications.
Correct Answer: Option 1 (Photodiode)
🧐 Not Sure What to Study Next?
Get a personalised study plan based on your goals, time and revision needs.
Shrillness of sound is determined by
Detailed Explanation:
Shrillness (or pitch) of sound is determined by the frequency of the sound wave.
Since frequency is inversely proportional to wavelength (f = v/λ, where v is constant in a given medium), wavelength determines pitch—shorter wavelength means higher frequency and shriller sound.
Amplitude determines loudness, not shrillness, while velocity depends on the medium and does not determine pitch.
Therefore, Option 3 (wavelength) is correct as it is directly related to frequency/pitch.
Large number of thin strips of black paint are made on the surface of a convex lens of focal length 20 cm to catch the image of a white horse. The image will be
Detailed Explanation:
Black paint strips block portions of the convex lens, reducing the amount of light passing through each section of the lens.
Every point on the horse emits light that passes through multiple parts of the lens, so blocking some strips reduces overall brightness but does not create stripes in the image—the image remains a complete horse with lower intensity.
Which one of the following statements is incorrect about muscles in human body?
Detailed Explanation:
❌ Statement 1 – Incorrect: Muscles can only pull the bone, not push; they work by contraction (pulling) and cannot actively push.
✅ Statement 2 – Correct: Muscles work in antagonistic pairs (e.g., biceps and triceps) – when one contracts (pulls), the other relaxes.
✅ Statement 3 – Correct: During contraction, muscle fibers become shorter, stiffer, and thicker as actin and myosin filaments slide over each other.
The most important cell type associated with the immunity of the body is
Detailed Explanation:
Lymphocytes are the most important cell type for body immunity.
Red Blood Cells (RBCs) transport oxygen, platelets aid in blood clotting, while lymphocytes (a type of White Blood Cell) produce antibodies and destroy pathogens, forming the core of the adaptive immune system.
Female Anopheles can be distinguished from female Culex because it sits
Detailed Explanation:
Female Anopheles mosquitoes rest with their bodies at an angle (approximately 45°) to the surface, with abdomen pointing upward.
Female Culex mosquitoes rest parallel to the surface with their bodies held horizontally.
This resting posture difference is a key morphological identification feature used in vector surveillance and malaria control programs.
In lichen, a chlorophyll-containing partner, _______ live together.
Detailed Explanation:
Lichens are classic examples of symbiotic associations between algae (or cyanobacteria) and fungi.
The algal partner (phycobiont) contains chlorophyll and performs photosynthesis, providing organic nutrients, while the fungal partner (mycobiont) provides protection, water, and minerals.
Therefore, Option 1 (algae and a fungus) is correct.
The parts of the skeleton that are not as hard as bones and which can be bent are called as
Detailed Explanation:
Cartilage is a flexible connective tissue found in various parts of the body, including joints, ears, nose, and larynx.
Vertebrae are the individual bones forming the spinal column, and carpals are the eight small bones in the wrist—both are hard bones, not flexible structures.
68th BPSC Prelims 2023 Questions Paper - Subject-wise Question Distribution
General Science
29 Qs (19.3%)Current Affairs
28 Qs (18.7%)Bihar Special
24 Qs (16%)Modern History
16 Qs (10.7%)Indian Polity
12 Qs (8%)General Mental Ability
9 Qs (6%)Indian Geography
7 Qs (4.7%)Indian Economy
7 Qs (4.7%)Medieval History
5 Qs (3.3%)Ancient History
5 Qs (3.3%)World Geography
5 Qs (3.3%)Environment & Ecology
3 Qs (2%)68th BPSC Prelims 2023 Question Paper - FAQs & Analysis
Q1 How many total questions were asked in 68th BPSC Prelims 2023?
Q2 What is the subject-wise question breakdown for 68th BPSC Prelims 2023?
- General Science: 29 questions (19.3%)
- Current Affairs: 28 questions (18.7%)
- Bihar Special: 24 questions (16%)
- Modern History: 16 questions (10.7%)
- Indian Polity: 12 questions (8%)
- General Mental Ability: 9 questions (6%)
- Indian Geography: 7 questions (4.7%)
- Indian Economy: 7 questions (4.7%)
- Medieval History: 5 questions (3.3%)
- Ancient History: 5 questions (3.3%)
- World Geography: 5 questions (3.3%)
- Environment & Ecology: 3 questions (2%)