Animated NEET Questions
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Physics · Projectile motion
A ball is thrown at 60° above the horizontal with a speed of 20 m/s. What is the maximum height it reaches? (g = 10 m/s²)
Answer: B · H = u² sin²θ / 2g = (400 × 3/4) / 20 = 15 m
Physics · Laws of motion
A block starts from rest and slides 10 m down a smooth incline of angle 30°. How long does it take? (g = 10 m/s²)
Answer: C · a = g sin 30° = 5 m/s². s = ½at² gives 10 = ½ × 5 × t², so t = 2 s
Physics · Oscillations
A simple pendulum of length 1 m makes small oscillations. What is its time period? (take g = π² m/s²)
Answer: D · T = 2π √(L/g) = 2π √(1/π²) = 2π × (1/π) = 2 s
Physics · Circular motion
A car moves round a circular track of radius 20 m at a constant speed of 10 m/s. What is the magnitude of its acceleration?
Answer: C · Speed is constant but direction changes: a = v²/r = 100/20 = 5 m/s², towards the centre
Physics · Ray optics
An object is placed 30 cm in front of a convex lens of focal length 20 cm. Where is the image formed?
Answer: B · 1/v − 1/u = 1/f: 1/v = 1/20 − 1/30 = 1/60, so v = +60 cm. Real, inverted, twice the size
Physics · Kinematics
A ball is dropped from rest from the top of an 80 m tall tower. How long does it take to reach the ground? (g = 10 m/s²)
Answer: B · h = ½gt² gives 80 = 5t², so t² = 16 and t = 4 s
Chemistry · States of matter
A gas occupies 2 L at 1 atm. Keeping the temperature constant, it is compressed to 0.5 L. What is its new pressure?
Answer: C · Boyle's law: P₁V₁ = P₂V₂ gives 1 × 2 = P₂ × 0.5, so P₂ = 4 atm
Zoology · Circulation
Which chamber of the human heart pumps oxygenated blood to all parts of the body?
Answer: D · The left ventricle, with the thickest wall, pumps oxygenated blood into the aorta for the whole body (systemic circulation)
Physics · Momentum
A trolley of mass m moving at 6 m/s hits an identical trolley at rest, and they stick together. What is their common velocity?
Answer: B · Momentum is conserved: m × 6 = 2m × v, so v = 3 m/s
Chemistry · Chemical kinetics
A first-order reaction has a half-life of 10 minutes. What fraction of the reactant is left after 30 minutes?
Answer: C · 30 min = 3 half-lives, so the fraction left is (1/2)³ = 1/8
Botany · Cell cycle
At which stage of mitosis do sister chromatids separate and move to opposite poles?
Answer: C · In anaphase the centromeres split and spindle fibres pull the sister chromatids (now chromosomes) to opposite poles
Physics · Motion graphs
A car starts from rest and accelerates uniformly to 20 m/s in 5 s. How far does it travel in this time?
Answer: B · Distance = area under the v-t graph = ½ × 5 × 20 = 50 m
Chemistry · States of matter
Under the same temperature and pressure, how many times faster does H₂ diffuse than O₂?
Answer: B · Graham's law: r(H₂)/r(O₂) = √(M(O₂)/M(H₂)) = √(32/2) = √16 = 4
Physics · Current electricity
A 3 Ω and a 6 Ω resistor are connected in parallel across a 12 V battery with no internal resistance. What current does the battery supply?
Answer: D · R = (3 × 6)/(3 + 6) = 2 Ω, so I = V/R = 12/2 = 6 A (4 A through 3 Ω, 2 A through 6 Ω)
Physics · Waves
A wave on a string has a frequency of 5 Hz and a wavelength of 2 m. What is its speed?
Answer: C · v = fλ = 5 × 2 = 10 m/s
Physics · Laws of motion
A 2 kg block on a rough floor (μ = 0.5) is pulled by a horizontal force of 20 N. What is its acceleration? (g = 10 m/s²)
Answer: B · Friction f = μmg = 0.5 × 2 × 10 = 10 N. Net force = 20 − 10 = 10 N, so a = 10/2 = 5 m/s²
Chemistry · Equilibrium
For N₂(g) + 3H₂(g) ⇌ 2NH₃(g) at equilibrium, the pressure is increased by compressing the gas. Which way does the equilibrium shift?
Answer: A · There are 4 moles of gas on the left and 2 on the right. Higher pressure favours the side with fewer gas moles, so the reaction shifts forward
Botany · Transport in plants
A plant cell is placed in a strong salt solution. Water leaves the cell and the protoplast shrinks away from the cell wall. What is this called?
Answer: B · In a hypertonic solution water moves out of the cell by osmosis. The protoplast shrinks away from the wall: this is plasmolysis
Physics · Oscillations
A 1 kg block is attached to a spring of spring constant 100 N/m on a smooth floor. What is the time period of its oscillation?
Answer: B · T = 2π√(m/k) = 2π√(1/100) = 2π/10 = π/5 s (about 0.63 s)
Chemistry · States of matter
A gas occupies 3 L at 300 K. At constant pressure it is heated to 400 K. What is its new volume?
Answer: C · Charles' law: V₁/T₁ = V₂/T₂, so V₂ = 3 × 400/300 = 4 L
Zoology · Molecular basis of inheritance
DNA with both strands labelled with ¹⁵N is replicated for two generations in a ¹⁴N medium. What fraction of the DNA molecules is hybrid (¹⁵N/¹⁴N)?
Answer: B · Replication is semi-conservative. After 2 generations there are 4 molecules: 2 hybrid and 2 fully light, so 2/4 = 1/2
Physics · Ray optics
A ray of light in air strikes a glass surface at an angle of incidence of 60°. If the refractive index of glass is √3, what is the angle of refraction?
Answer: A · Snell's law: sin 60° = √3 sin r, so sin r = (√3/2)/√3 = 1/2 and r = 30°
Chemistry · Structure of atom
How many unpaired electrons does a nitrogen atom (Z = 7) have in its ground state?
Answer: C · N is 1s² 2s² 2p³. By Hund's rule the three 2p electrons occupy separate orbitals with the same spin, so there are 3 unpaired electrons
Botany · Principles of inheritance
Two heterozygous tall pea plants (Tt) are crossed. What is the phenotypic ratio of the offspring?
Answer: C · Tt × Tt gives TT, Tt, Tt and tt. Three of them have T (tall) and one is tt (dwarf), so the phenotypic ratio is 3 : 1 (genotypic 1 : 2 : 1)
Physics · Relative motion
Two cars 100 m apart move towards each other on a straight road at 10 m/s and 15 m/s. After how much time do they meet?
Answer: B · Relative speed = 10 + 15 = 25 m/s, so time = 100/25 = 4 s
Chemistry · Mole concept
4 g of hydrogen burns completely in excess oxygen: 2H₂ + O₂ → 2H₂O. What mass of water is formed?
Answer: C · 4 g H₂ = 2 mol. 2 mol H₂ give 2 mol H₂O = 2 × 18 = 36 g
Zoology · Breathing and exchange of gases
During inspiration (breathing in), what happens to the diaphragm?
Answer: B · The diaphragm contracts and flattens and the external intercostal muscles lift the ribs. Chest volume rises, lung pressure falls and air flows in
Physics · Laws of motion
A 60 kg person stands on a weighing scale in a lift that accelerates upward at 2 m/s². What does the scale read? (g = 10 m/s²)
Answer: C · N − mg = ma, so N = m(g + a) = 60 × 12 = 720 N
Botany · Photosynthesis
The oxygen released during photosynthesis comes from which molecule?
Answer: C · In the light reaction water is split (photolysis): 2H₂O → 4H⁺ + 4e⁻ + O₂. Isotope studies showed that the O₂ comes from water, not CO₂
Physics · Mechanical properties of fluids
A wooden block floats in water with three-fourths of its volume submerged. What is the density of the wood? (density of water = 1000 kg/m³)
Answer: C · Weight = buoyant force: ρ(wood) × V × g = 1000 × ¾V × g, so ρ(wood) = 750 kg/m³