74651. In considering friction of a V-thread, the virtual coefficient of friction (μ1) is given by
74652. The wear of bearing is proportional to velocity and pressure.
74653. In a shaper mechanism, the coriolis component of acceleration does not exist.
74654. In a gear having involute teeth, the normal to the involute is a tangent to the
74655. A body is said to be under forced vibrations, when
74656. The natural frequency of free longitudinal vibrations is equal to (where m = Mass of the body, s = Stiffness of the body, and δ = Static deflection of the body)
74657. The radius of a friction circle for a shaft rotating inside a bearing is (where r = Radius of shaft, and tan φ = Coefficient of friction between the shaft and bearing)
74658. The maximum and minimum value of the tractive force is given by
74659. In a turning moment diagram, the variations of energy above and below the mean resisting torque line is called
74660. In a spring controlled governor, when the controlling force __________ as the radius of rotation increases, it is said to be a stable governor.
74661. The distance between the centre of suspension and centre of percussion is equal to the equivalent length of a simple pendulum.
74662. When the body is suspended at the point of suspension, its periodic time and frequency will be __________ as compared to the body suspended at the point of percussion.
74663. The working depth of a gear is the radial distance from the
74664. The acceleration of a particle at any instant has two components i.e. radial component and tangential component. These two components will be
74665. When the axes of the first and last wheels are co-axial, then the train is known as
74666. The primary unbalanced force is more than the secondary unbalanced force.
74667. The cam and follower is an example of
74668. The danger of breakage and vibration is maximum
74669. The primary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, θ = Angle of inclination of crank with the line of stroke, and n = Ratio of the lengm of connecting rod to radius of crank)
74670. For two governors A and B, the lift of sleeve of governor A is more than that of governor B, for a given fractional change in speed. It indicates that
74671. The component of the acceleration, parallel to the velocity of the particle, at the given instant is called
74672. In a multiple V-belt drive, if one of the belt is broken, then we should replace
74673. The swaying couple is due to the
74674. The lead screw of a lathe with nut forms a
74675. In under damped vibrating system, if x1 and x2 are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to
74676. The angle of the inclined plane at which the body just begins to slide down the plane, is called helix angle.
74677. In forced vibrations, the magnitude of damping force at resonance is equal to the impressed force.
74678. When a slider moves on a fixed link having curved surface, their instantaneous centre lies
74679. Scotch yoke mechanism is used to generate
74680. The unbalanced primary forces in a reciprocating engine are
74681. The balancing of a rigid rotor can be achieved by appropriately placing balancing masses in
74682. The frictional torque transmitted in a conical pivot bearing with assumption of uniform pressure is __________ as compared to uniform wear.
74683. The displacement of the D-slide valve is __________ the steam lap by a distance known as lead of the valve.
74684. In the two rotor system as shown in the below figure (I1 < I2), a node of vibration is situated
74685. For static balancing of a shaft, the net dynamic force acting on the shaft is equal to zero.
74686. A spring controlled governor is said to be unstable, if the relation between the controlling force (Fc) and radius of rotation (r) is Fc = ar.
74687. The rotor of a ship rotates in clockwise direction when viewed from stern and the ship takes a left turn. The effect of gyroscopic couple acting on it will be
74688. Most of the engines, generally, do not require balancing of secondary forces and couples.
74689. The secondary unbalanced force is maximum __________ in one revolution of the crank.
74690. A spring controlled governor is found unstable. It can be made stable by
74691. In order to have a good grip on the pulley, the V-belt should touch the bottom of the groove in the pulley.
74692. In order to double the period of a simple pendulum, the length of the string should be
74693. When a rigid body is suspended vertically and it oscillates with a small amplitude under the action of the force of gravity, the body is known as
74694. Longitudinal vibrations are said to occur when the particles of a body moves
74695. The velocity of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by (where ω = Angular velocity of the cam shaft)
74696. The sensitiveness of the governor __________ as the speed range decreases.
74697. In Meyer's expansion valve, the expansion valve is driven by an eccentric having an angle of advance from
74698. The frictional torque transmitted in a flat pivot bearing, considering uniform wear, is (where μ = Coefficient of friction, W = Load over the bearing, and R = Radius of bearing surface)
74699. If the damping factor for a vibrating system is unity, then the system will be
74700. In vibration isolation system, if ω/ωn < 2 , then for all values of damping factor, the trans-missibility will be (where ω = Angular speed of the system, ωn = Natural frequency of vibration of the system)