GATE ME 2015 Set 3 — Question 13

MCQ+1 / -0.33EasySimple, Compound & Epicyclic TrainsCams, Gears & Gear TrainsTheory of Machines & Vibrations

Theory of Machines & Vibrations → Cams, Gears & Gear Trains → Simple, Compound & Epicyclic Trains

Last updated 5 September 2026

Question

N_2, N_3, N_4, N_5

Correct answer (C) Only 5 Solution An idler gear is an intermediate gear in a gear train that meshes with both a preceding and a succeeding gear in a simple mesh sequence. It changes the direction of rotation but does not affect the overall gear ratio. In the given compound gear train: 1. Gear 2 (driver) meshes with Gear 3. 2. Gear 3 and Gear 4 are on the same shaft (compound gear). 3. Gear 4 meshes with Gear 5. 4. Gear 5 meshes with Gear 6 (driven). Gear 5 is the only gear that meshes with both a preceding gear (Gear 4) and a succeeding gear (Gear 6), thus acting as an idler. Gear 3 is not an idler because it is part of a compound gear and does not mesh with Gear 4. Therefore, only gear 5 acts as an idler. Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

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Correct answer (C) Only 5 Solution An idler gear is an intermediate gear in a gear train that meshes with both a preceding and a succeeding gear in a simple mesh sequence. It changes the direction of rotation but does not affect the overall gear ratio. In the given compound gear train: 1. Gear 2 (driver) meshes with Gear 3. 2. Gear 3 and Gear 4 are on the same shaft (compound gear). 3. Gear 4 meshes with Gear 5. 4. Gear 5 meshes with Gear 6 (driven). Gear 5 is the only gear that meshes with both a preceding gear (Gear 4) and a succeeding gear (Gear 6), thus acting as an idler. Gear 3 is not an idler because it is part of a compound gear and does not mesh with Gear 4. Therefore, only gear 5 acts as an idler.

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