Theory of Machine When the two elements of a pair have __________ when in motion, it is said to a lower pair. Surface contact Body contact Line or point contact None of these Surface contact Body contact Line or point contact None of these ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine A rotor which is balanced statically but not dynamically is supported on two bearings L apart and at high speed of the rotor, reaction on the left bearing is R. The right side of the bearing is shifted to a new position 2L apart from the left bearing. At the same rotor speed, dynamic reaction on the left bearing in the new arrangement will Become equal to R/4 Remain same as before Become equal to 2R Become equal to R/2 Become equal to R/4 Remain same as before Become equal to 2R Become equal to R/2 ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine In a Hartnell governor, the lift of the sleeve is given by (where r₁ and r₂ = Max. and min. radii of rotation, x = Length of ball arm of the lever, and y = Length of sleeve arm of the lever) (r₁ + r₂) (x/y) (r₁ - r₂) (y/x) (r₁ + r₂) (y/x) (r₁ - r₂) (x/y) (r₁ + r₂) (x/y) (r₁ - r₂) (y/x) (r₁ + r₂) (y/x) (r₁ - r₂) (x/y) ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine In a vibrating system, if the actual damping coefficient is 40 N/m/s and critical damping coefficient is 420 N/m/s, then logarithmic decrement is equal to 0.8 0.6 0.4 0.2 0.8 0.6 0.4 0.2 ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine A body is said to be under forced vibrations, when A body vibrates under the influence of external force There is a reduction in amplitude after every cycle of vibration No external force acts on a body, after giving it an initial displacement None of these A body vibrates under the influence of external force There is a reduction in amplitude after every cycle of vibration No external force acts on a body, after giving it an initial displacement None of these ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine The static balancing is satisfactory for low speed rotors but with increasing speeds, dynamic balancing becomes necessary. This is because, the Unbalanced couples are caused only at higher speeds Unbalanced forces are not dangerous at higher speeds Effects of unbalances are directly proportional to the speed Effects of unbalances are proportional to the square of the speed Unbalanced couples are caused only at higher speeds Unbalanced forces are not dangerous at higher speeds Effects of unbalances are directly proportional to the speed Effects of unbalances are proportional to the square of the speed ANSWER DOWNLOAD EXAMIANS APP
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