NEET doubts
500 doubts found
What is the difference between systematic error and random error?
Systematic errors are consistent and one-directional (fixable by calibration); random errors scatter both ways (reduced by averaging).
What is the difference between distance and displacement?
Distance is the total path length (scalar, never decreases); displacement is the straight-line vector from start to finish (can be zero on a round trip).
What is the difference between static friction and kinetic friction?
Static friction acts on a stationary object and self-adjusts up to a limit; kinetic friction acts on a sliding object and is roughly constant (and usually smaller).
What is the difference between elastic collision and inelastic collision?
Both conserve momentum; an elastic collision also conserves kinetic energy, while an inelastic one converts some KE into heat/deformation.
What is the difference between torque and force?
Force causes linear acceleration; torque causes angular acceleration and depends on where the force is applied.
What is the difference between orbital velocity and escape velocity?
Orbital velocity keeps a satellite in a circular orbit; escape velocity (√2 times larger) lets it leave gravity forever.
What is the difference between C_p and C_v?
C_p (constant pressure) exceeds C_v (constant volume) because at constant pressure some heat also does expansion work.
What does “The mole” actually mean in Some Basic Concepts (Mole Concept), and why does it matter for NEET?
a counting unit for particles — one mole is 6.022×10²³ (Avogadro's number) of anything.
What does “Quantum numbers” actually mean in Structure of Atom, and why does it matter for NEET?
four numbers (n, l, m, s) that pin down an electron's shell, subshell, orbital orientation and spin.
What does “Octet rule” actually mean in Chemical Bonding & Molecular Structure, and why does it matter for NEET?
atoms tend to gain, lose or share electrons to reach eight in their outer shell.
What does “Enthalpy (H)” actually mean in Chemical Thermodynamics, and why does it matter for NEET?
the heat content at constant pressure; ΔH is negative for exothermic and positive for endothermic reactions.
What does “Dynamic equilibrium” actually mean in Equilibrium, and why does it matter for NEET?
the state where forward and reverse reactions occur at equal rates, so concentrations stay constant.
What does “Oxidation and reduction” actually mean in Redox Reactions, and why does it matter for NEET?
oxidation is loss of electrons and reduction is gain of electrons (remember OIL RIG).
What does “Atomic radius trend” actually mean in Periodic Table & Periodicity, and why does it matter for NEET?
atomic size decreases across a period (more nuclear pull) and increases down a group (new shells).
What does “Order of reaction” actually mean in Chemical Kinetics, and why does it matter for NEET?
the power to which a reactant's concentration is raised in the experimentally-determined rate law.
What does “Types of cells” actually mean in Electrochemistry, and why does it matter for NEET?
a galvanic cell turns a spontaneous reaction into electricity; an electrolytic cell uses electricity to drive a non-spontaneous reaction.
What does “Inductive effect” actually mean in Organic Chemistry — Basic Concepts, and why does it matter for NEET?
a permanent shift of electron density through sigma bonds due to electronegativity differences.
What does “Saturation” actually mean in Hydrocarbons, and why does it matter for NEET?
alkanes are saturated (only single bonds); alkenes and alkynes are unsaturated (double or triple bonds).
I keep getting “The mole” questions wrong in Some Basic Concepts (Mole Concept). What's the trap?
confusing number of moles with number of grams or molecules.
I keep getting “Quantum numbers” questions wrong in Structure of Atom. What's the trap?
confusing the principal quantum number n (shell) with l (subshell).
I keep getting “Octet rule” questions wrong in Chemical Bonding & Molecular Structure. What's the trap?
forcing an octet on exceptions like BeCl₂, BF₃ or SF₆.
I keep getting “Enthalpy (H)” questions wrong in Chemical Thermodynamics. What's the trap?
getting the sign of ΔH the wrong way round.
I keep getting “Dynamic equilibrium” questions wrong in Equilibrium. What's the trap?
thinking the reaction has stopped at equilibrium.
I keep getting “Oxidation and reduction” questions wrong in Redox Reactions. What's the trap?
mixing up which process loses and which gains electrons.