NEET 2018 (question paper code EE) had 179 questions in NEET720's bank: Physics 45, Chemistry 44, Botany 45 and Zoology 45. The 12 questions below are a fixed free sample with NEET720's explanations; the complete paper is in the app, where it can be sat as a timed mock with the real marking scheme.
Physics — NEET 2018 sample questions
NEET 2018 · Question 1
At what temperature does the rms speed of oxygen molecules equal Earth's escape speed 11.2 km/s? Take m(O₂)=2.76×10⁻²⁶ kg and kB=1.38×10⁻²³ J K⁻¹.
- A.2.51×10⁴ K
- B.5.02×10⁴ K
- C.8.36×10⁴ K
- D.1.25×10⁴ K
Show answer and explanation
Answer: C. 8.36×10⁴ K
Set vrms=√(3kBT/m)=11.
Set vrms=√(3kBT/m)=11.2×10³ m/s. Solving T=mv²/(3kB) gives approximately 8.36×10⁴ K. Therefore the answer is “8.36×10⁴ K”. The distractors fail the governing formula, units, sign convention or numerical substitution.
NEET 2018 · Question 2
A monatomic ideal gas follows an isobaric path from A to B. What is the ratio of work done by the gas to heat absorbed?
- A.2/5
- B.1/3
- C.2/3
- D.2/7
Show answer and explanation
Answer: A. 2/5
For an isobaric process W=nRΔT and Q=nCpΔT with Cp=5R/2 for a monatomic gas.
For an isobaric process W=nRΔT and Q=nCpΔT with Cp=5R/2 for a monatomic gas. Hence W/Q=R/(5R/2)=2/5. Therefore the answer is “2/5”. The distractors fail the governing formula, units, sign convention or numerical substitution.
NEET 2018 · Question 3
What is the efficiency of a Carnot engine operating between 100°C and 0°C?
- A.26.8%
- B.6.25%
- C.20%
- D.12.5%
Show answer and explanation
Answer: A. 26.8%
Carnot efficiency is 1−Tc/Th with temperatures in kelvin.
Carnot efficiency is 1−Tc/Th with temperatures in kelvin. Thus η=1−273/373≈0.268=26.8%. Therefore the answer is “26.8%”. The distractors fail the governing formula, units, sign convention or numerical substitution.
Chemistry — NEET 2018 sample questions
NEET 2018 · Question 46
Given van der Waals constant a: NH₃=4.17, H₂=0.244, O₂=1.36, CO₂=3.59. Which gas is easiest to liquefy?
- A.NH₃
- B.O₂
- C.H₂
- D.CO₂
Show answer and explanation
Answer: A. NH₃
A larger van der Waals a indicates stronger intermolecular attraction.
A larger van der Waals a indicates stronger intermolecular attraction. NH₃ has the largest a and is therefore easiest to liquefy. Therefore the answer is “NH₃”. The other choices conflict with the relevant reaction mechanism, bonding model, equilibrium relation or periodic trend.
NEET 2018 · Question 47
Which mixture of NaOH and HCl forms an acidic buffer after mixing?
- A.Pure excess strong acid
- B.Pure excess strong base
- C.Exactly neutral NaCl solution
- D.A weak-acid/conjugate-base mixture equivalent to the fourth listed composition
Show answer and explanation
Answer: D. A weak-acid/conjugate-base mixture equivalent to the fourth listed composition
A buffer requires appreciable amounts of a weak acid/base and its conjugate partner.
A buffer requires appreciable amounts of a weak acid/base and its conjugate partner. Complete neutralisation or excess strong acid/base does not provide buffer action. Therefore the answer is “A weak-acid/conjugate-base mixture equivalent to the fourth listed composition”. The other choices conflict with the relevant reaction mechanism, bonding model, equilibrium relation or periodic trend.
NEET 2018 · Question 48
BaSO₄ solubility in water is 2.42×10⁻³ g L⁻¹ at 298 K. Molar mass=233 g/mol. Find Ksp.
- A.≈1.08×10⁻¹⁰
- B.1.08×10⁻¹⁴
- C.1.08×10⁻¹²
- D.1.08×10⁻⁸
Show answer and explanation
Answer: A. ≈1.08×10⁻¹⁰
Molar solubility s=2.
Molar solubility s=2.42×10⁻³/233≈1.04×10⁻⁵ M. For BaSO₄, Ksp=s²≈1.08×10⁻¹⁰. Therefore the answer is “≈1.08×10⁻¹⁰”. The other choices conflict with the relevant reaction mechanism, bonding model, equilibrium relation or periodic trend.
Botany — NEET 2018 sample questions
NEET 2018 · Question 91
Which statement about gymnosperms is correct?
- A.Ovules are not enclosed by an ovary wall
- B.Horsetails are gymnosperms
- C.Selaginella is heterosporous but Salvinia homosporous
- D.Cycas and Cedrus both have unbranched stems
Show answer and explanation
Answer: A. Ovules are not enclosed by an ovary wall
Gymnosperm ovules are exposed or 'naked' because no ovary encloses them.
Gymnosperm ovules are exposed or 'naked' because no ovary encloses them. The other statements misclassify or overgeneralise taxa. Therefore the answer is “Ovules are not enclosed by an ovary wall”. The other choices describe a different biological structure, process, taxon or physiological relationship.
NEET 2018 · Question 92
Pneumatophores are characteristic of:
- A.Halophytes/mangroves
- B.Carnivorous plants
- C.Free-floating hydrophytes
- D.Submerged hydrophytes
Show answer and explanation
Answer: A. Halophytes/mangroves
Mangrove roots growing in oxygen-poor mud send negatively geotropic aerial roots upward.
Mangrove roots growing in oxygen-poor mud send negatively geotropic aerial roots upward. Their lenticels enable gaseous exchange. Therefore the answer is “Halophytes/mangroves”. The other choices describe a different biological structure, process, taxon or physiological relationship.
NEET 2018 · Question 93
Sweet potato is a modified:
- A.Stem
- B.Tap root
- C.Adventitious root
- D.Rhizome
Show answer and explanation
Answer: C. Adventitious root
Sweet potato stores food in swollen adventitious roots arising from stem nodes, unlike potato which is a stem tuber.
Sweet potato stores food in swollen adventitious roots arising from stem nodes, unlike potato which is a stem tuber. Therefore the answer is “Adventitious root”. The other choices describe a different biological structure, process, taxon or physiological relationship.
Zoology — NEET 2018 sample questions
NEET 2018 · Question 136
Match glycosuria, gout, renal calculi and glomerulonephritis with their defining features.
- A.Glucose in urine; urate crystals in joints; kidney stones; inflamed glomeruli
- B.Protein in urine; low glucose; anaemia; asthma
- C.Urate in urine; low calcium; nephron loss; hypertension
- D.All four are identical renal conditions
Show answer and explanation
Answer: A. Glucose in urine; urate crystals in joints; kidney stones; inflamed glomeruli
The four terms describe distinct conditions: urinary glucose, uric-acid deposition in joints, crystalline kidney stones and inflammation of renal glomeruli.
The four terms describe distinct conditions: urinary glucose, uric-acid deposition in joints, crystalline kidney stones and inflammation of renal glomeruli. Therefore the answer is “Glucose in urine; urate crystals in joints; kidney stones; inflamed glomeruli”. The other choices describe a different biological structure, process, taxon or physiological relationship.
NEET 2018 · Question 137
Ultrafiltration of blood in the nephron occurs at:
- A.Loop of Henle
- B.Ureter
- C.Malpighian corpuscle/glomerulus
- D.Urinary bladder
Show answer and explanation
Answer: C. Malpighian corpuscle/glomerulus
High glomerular hydrostatic pressure drives plasma water and small solutes through the filtration barrier into Bowman's capsule.
High glomerular hydrostatic pressure drives plasma water and small solutes through the filtration barrier into Bowman's capsule. Therefore the answer is “Malpighian corpuscle/glomerulus”. The other choices describe a different biological structure, process, taxon or physiological relationship.
NEET 2018 · Question 138
Concentration of urine is strongly associated with:
- A.Loop of Henle counter-current mechanism
- B.Ureter
- C.Urinary bladder
- D.Renal artery only
Show answer and explanation
Answer: A. Loop of Henle counter-current mechanism
Counter-current multiplication creates the medullary osmotic gradient that permits water reabsorption and concentrated urine.
Counter-current multiplication creates the medullary osmotic gradient that permits water reabsorption and concentrated urine. Therefore the answer is “Loop of Henle counter-current mechanism”. The other choices describe a different biological structure, process, taxon or physiological relationship.
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Questions about NEET 2018
How many questions were there in NEET 2018?＋
The NEET 2018 paper in NEET720's bank (code EE) has 179 questions: Physics 45, Chemistry 44, Botany 45 and Zoology 45.
Where can I solve the full NEET 2018 paper?＋
Sign in to NEET720, open Previous Year Questions and choose 2018. You can practise question by question with instant explanations, or sit the whole paper as a timed mock with the real +4/−1 marking and a full analysis afterwards.
Are these the official NEET 2018 questions?＋
The questions and options reproduce the official NTA paper as published. Every explanation is NEET720's own; none is copied from any publisher or coaching institute. Questions that NTA declared bonus or withdrew are not shown as practice items.
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Questions and options reproduce the official NTA NEET 2018 paper. Explanations are written by NEET720. NEET720 is not affiliated with the National Testing Agency.