type: $pyq_{analysis}$ | topic: NEET-PYQ-patterns

Pattern 1: Vernier Caliper Reading + Zero Error (appears almost every year)

Format: Diagram showing Vernier scale with main scale reading and coinciding division; specify zero error sign and value. Ask: Calculate corrected reading. Common trap: Adding positive zero error (should subtract) — "Positive → Subtract." Example PYQ format: "Main scale reading = 42 mm, 18th Vernier division coincides, positive zero error = 0.06 mm. Find corrected reading." → 42.30 mm.

Pattern 2: Resonance Tube — Speed of Sound / End Correction

Format: Give $l_{1}$ and $l_{2}$ and frequency; ask speed of sound or end correction. Trick question: "Using v = 4$fl_{1}$ vs v = 2f($l_{2}$−$l_{1}$) — which is better?" → Always prefer two-resonance formula. Key formula to drill: v = 2f($l_{2}$−$l_{1}$); e = $\frac{l_{2}−3l_{1}}{2}$.

Pattern 3: Graph Interpretation

Types seen:

• $T^{2}$ vs l for pendulum: slope = 4π^{2}/g → ask for g
• V-I graph: ask ohmic vs non-ohmic; slope = R
• i-delta graph: ask condition at minimum of U-curve → i = e
• 1/v vs 1/u: ask for f from intercepts

Pattern 4: Metre Bridge Calculation

Format: Balance at l cm, known resistance R; find S. Or: interchange R and S; find new balance. Formula: R/S = $\frac{l}{100−l}$; interchange → l' = 100−l.

Pattern 5: Semiconductor I-V Characteristics

Format: Description or sketch of I-V curve; ask threshold voltage, or identify device (Si diode, Ge diode, Zener, LED). Key values: Si: 0.7V; Ge: 0.3V; LED: 1.5–3V; Zener: operates in reverse at $V_Z$.

Pattern 6: Assertion-Reason (new NEET format)

Common topics: Zero error correction logic; end correction in resonance tube; minimum deviation condition in prism; Zener diode regulation.

Frequency of Topics (2019–2024)