1. the contact ratio is.......
(a)zero
(b)more than one
(c)less than one
(d)none of these
2. the ratio of maximum displacement of the forced vibration to the deflection due to the static force is known as................
(a)damping factor
(b)magnification factor
(c)damping coefficient
(d)logarithmic coefficient
4. when the sleeve of a porter governor moves upwards, the governor height.....
(a)increases
(b)decreases
(c)remains unaffected
(d)none of the above
5. the coriolis component of acceleration is taken into account for ...........
(a)slider crank mechanism
(b)four bar chain mechanism
(c)quick return motion mechanism
(d)none of the above
all answer required
contact ratio of gear is
1.b
2.b
4.a
5.d
1. To determine the contact ratio, which is the ratio of the period of tooth contact to the period of one tooth, you will need information about the gears or the gear design. The contact ratio can be calculated by dividing the number of teeth in the mating gears by the number of teeth on the pinion gear.
For example, if you have a gear with 40 teeth and another gear with 20 teeth, the contact ratio would be 40/20 = 2. This means that for every tooth on the pinion gear, there are two teeth in contact with the mating gear.
Based on the given options, if the contact ratio is zero, it means there is no contact between the gears. If the contact ratio is more than one, it means there are multiple teeth in contact with the mating gear. If the contact ratio is less than one, it means there is less than one tooth in contact with the mating gear. Therefore, the correct answer would be (c) less than one.
2. The ratio of maximum displacement of the forced vibration to the deflection due to the static force is known as the magnification factor. To calculate the magnification factor, you will need to determine the maximum displacement (amplitude) of the forced vibration and the deflection caused by the static force.
The magnification factor can be calculated by dividing the maximum displacement by the deflection due to the static force. It represents the amplification of the vibration compared to the static deflection.
Damping factor (a) and damping coefficient (c) are related to the amount of damping in a vibrating system. Logarithmic coefficient (d) is not directly related to the ratio described in the question. Therefore, the correct answer would be (b) magnification factor.
4. The movement of the sleeve in a porter governor determines the effective length of the governor arms and affects the governor height. When the sleeve of a porter governor moves upwards, the governor height increases. This is because the upward movement of the sleeve increases the distance between the pivot point and the center of mass of the balls or weights, causing the governor arms to extend and the height of the governor to increase. Therefore, the correct answer would be (a) increases.
5. The Coriolis component of acceleration is taken into account in mechanisms that involve rotational motion and velocity, such as the slider crank mechanism, four bar chain mechanism, and quick return motion mechanism. The Coriolis component of acceleration arises from the interaction between rotational motion and linear velocity.
Therefore, none of the given options (a) slider crank mechanism, (b) four bar chain mechanism, or (c) quick return motion mechanism, can be considered as the correct answer, as all of them should take into account the Coriolis component of acceleration. The correct answer would be (d) none of the above.