NEET Physics Numericals 2027 — Most Important Problems with Solutions

Physics is the most feared section among NEET aspirants — yet it’s also the most predictable. The same types of numericals appear year after year. This guide covers the most important NEET Physics numericals with step-by-step solutions, organized by chapter.

NEET Physics Numerical Weightage — Chapter-wise Analysis

Important NEET Physics Numericals — Chapter-wise

1. Modern Physics — Photoelectric Effect

Key Formulas:

• Einstein’s photoelectric equation: KE_max = hν – φ = hν – hν₀
• de Broglie wavelength: λ = h/mv = h/p
• Energy of photon: E = hν = hc/λ
• Nuclear decay: N = N₀e^–λt | Half-life: T½ = 0.693/λ

Problem 1 (NEET PYQ type): The threshold frequency for photoelectric emission from a metal surface is 5 × 10¹⁴ Hz. If light of frequency 7 × 10¹⁴ Hz is incident on it, what is the maximum kinetic energy of emitted photoelectrons? (h = 6.6 × 10⁻³⁴ J·s)

Solution:

KE_max = h(ν – ν₀) = 6.6 × 10⁻³⁴ × (7 – 5) × 10¹⁴
= 6.6 × 10⁻³⁴ × 2 × 10¹⁴
= 1.32 × 10⁻¹⁹ J

Problem 2: A radioactive substance has a half-life of 20 minutes. What fraction of the original substance remains after 1 hour?

Solution:

Number of half-lives in 60 min = 60/20 = 3
Fraction remaining = (1/2)³ = 1/8

2. Optics — Lens Formula & Mirror Formula

Key Formulas:

• Mirror formula: 1/f = 1/v + 1/u
• Lens formula: 1/f = 1/v – 1/u
• Magnification (mirror): m = –v/u
• Snell’s law: n₁ sin θ₁ = n₂ sin θ₂
• Lens maker’s formula: 1/f = (n–1)(1/R₁ – 1/R₂)

Problem 1: An object is placed 15 cm from a concave mirror of focal length 10 cm. Find the image distance.

Solution:

Using mirror formula: 1/f = 1/v + 1/u
f = –10 cm (concave), u = –15 cm
1/(–10) = 1/v + 1/(–15)
1/v = –1/10 + 1/15 = –3/30 + 2/30 = –1/30
v = –30 cm (real, inverted image, same side as object)

Problem 2 (NEET 2023 type): A convex lens has focal length 20 cm. An object is placed at 30 cm. Find image position and magnification.

Solution:

1/f = 1/v – 1/u → f = +20 cm, u = –30 cm
1/20 = 1/v – 1/(–30) = 1/v + 1/30
1/v = 1/20 – 1/30 = 3/60 – 2/60 = 1/60
v = +60 cm (real image, other side)
m = v/u = 60/(–30) = –2 (inverted, 2× magnified)

3. Current Electricity — Ohm’s Law & Circuits

Key Formulas:

• Ohm’s Law: V = IR
• Resistors in series: R_total = R₁ + R₂ + R₃
• Resistors in parallel: 1/R_total = 1/R₁ + 1/R₂ + 1/R₃
• Power: P = VI = I²R = V²/R
• Kirchhoff’s Laws: ΣV = 0 (voltage), ΣI = 0 (current)

Problem 1: Three resistors of 2Ω, 3Ω, and 6Ω are connected in parallel. Find the equivalent resistance.

Solution:

1/R = 1/2 + 1/3 + 1/6 = 3/6 + 2/6 + 1/6 = 6/6 = 1
R = 1 Ω

Problem 2: A bulb rated 100W at 220V. What is its resistance? What current flows through it?

Solution:

R = V²/P = (220)²/100 = 48400/100 = 484 Ω
I = P/V = 100/220 = 0.45 A

4. Thermodynamics

Key Formulas:

• First Law: ΔU = Q – W
• Ideal gas: PV = nRT
• Carnot efficiency: η = 1 – T₂/T₁ = (T₁ – T₂)/T₁

Problem 1: A Carnot engine operates between 500 K and 300 K. Find its efficiency.

Solution:

η = 1 – T₂/T₁ = 1 – 300/500 = 1 – 0.6 = 0.4 = 40%

NEET Physics Numerical Solving Strategy

1. Write down given data — Don’t skip this; it saves time in pressure situations
2. Identify the formula — From your formula sheet, identify the right equation
3. Check units — Convert everything to SI units before substituting
4. Estimate first — NEET is MCQ; eliminate clearly wrong options before calculating
5. Learn “standard NEET numbers” — g = 10 m/s², h = 6.6 × 10⁻³⁴, e = 1.6 × 10⁻¹⁹

High-Yield Formulas for NEET Physics (Quick Reference)