GATE AG 2013 • Q11 MCQ • 1 Mark

Section 3: Farm Power

Tractors and Power Tillers

Subtopic: Human engineering and safety considerations in design of tractor and agricultural implements

Question Statement:

During a test, sound level was measured as 90 dB in the operator's cabin on a tractor. Taking reference sound pressure as 2×10⁻⁵ N m⁻², the measured RMS sound pressure in N m⁻² is

Options:

  • (A) 6.32×10⁻¹
  • (B) 6.32×10¹
  • (C) 31.8×10⁻³
  • (D) 6.32×10⁻⁴

Official Answer Key:

A

Step-by-Step Solution & Explanation

Sound pressure level, L_p = 20×log₁₀(p/p_ref) ⇒ p = p_ref × 10^(L_p/20). p = 2×10⁻⁵ × 10^(90/20) = 2×10⁻⁵ × 10^4.5 = 2×10⁻⁵ × 31,623 = 0.632 N/m² (6.32×10⁻¹ N/m²). Answer: option matching 6.32×10⁻¹.

Practice This in Real CBT Exam Interface

Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.

Launch CBT Mock Test