Correct Answer - Option 2 : Only one curve is required to cut
Explanation:
The involute profile of teeth is preferred over the cycloidal profile of teeth because only one curve is required to cut.
Involute teeth have a number of benefits as compared to the Cycloidal profile as mentioned in the given table.
Cycloidal teeth
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Involute teeth
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A cycloid is the locus of a point on the circumference of a circle that rolls without slipping on the straight line.
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An involute is defined as the locus of a point on a straight line which rolls without slipping on the circumference of a circle.
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It involves a double curve for the teeth, epicycloid and hypocycloid. This complicates the manufacture.
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It involves a single curve for the teeth resulting in the simplicity of manufacture and tools.
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The pressure angle varies from a maximum at the beginning of the engagement, reduces to zero at the pitch point and again increases to a maximum at the end of engagement resulting in the less smooth running of the gears.
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The pressure angle is constant throughout the engagement of teeth. This results in the smooth running of gears.
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Owing to the difficulty of manufacture, these are costlier.
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These are simple to manufacture and thus are cheaper.
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Exact centre-distance is required to transmit a constant velocity ratio.
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A little variation does not affect the velocity ratio.
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The phenomenon of interference does not occur at all.
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Interference can occur if the condition of the minimum number of teeth on a gear is not followed.
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