Efficiency of a screw jack in maximum when its 31 helix angle, ? is a.45 + ?/2 b.107 dynes c.? d.45 - ?/2 e.45?

Efficiency of a screw jack in maximum when its 31 helix angle, ? is a.45 + ?/2 b.107 dynes c.? d.45 - ?/2 e.45?
by

1 Answer

Answer :

d. 45 - ?/2
by

Related questions

A screw jack has 4 threads per inch. The mean radius of the thread is 2.338 inches. The mean diameter of the bearing surface under the cap is 3.25 inches. What is the turning moment required to raise the bload of 150 kg ( a.5.61 kg-inch b.50.6 kg-inch c.107 dynes d.30.3 kg-inch e.23.6 kg-inch

Description : A screw jack has 4 threads per inch. The mean radius of the thread is 2.338 inches. The mean diameter of the bearing surface under the cap is 3.25 inches. What is the turning moment required to raise the bload of 150 kg ( a.5.61 kg-inch b.50.6 kg-inch c.107 dynes d.30.3 kg-inch e.23.6 kg-inch

Last Answer : b. 50.6 kg-inch

A block slides down a frictionless incline making an angle ? with an elevator floor. The acceleration relative to the incline will be maximum when a.the elevator ascends at constant speed v b.the elevator descends at constant speed v c.107 dynes d.elevator descends with deceleration a e.the elevator descends with acceleration a

Description : A block slides down a frictionless incline making an angle ? with an elevator floor. The acceleration relative to the incline will be maximum when a.the elevator ascends at constant speed v b. ... speed v c.107 dynes d.elevator descends with deceleration a e.the elevator descends with acceleration a

Last Answer : d. elevator descends with deceleration a

A imaginary planet has half the mass and half the radius of the earth. The acceleration of gravity at its surface would be a.9.8 m/s2 b.107 dynes c.4.9 m/s2 d.19.6 m/s2 e.2.45 m/s2

Description : A imaginary planet has half the mass and half the radius of the earth. The acceleration of gravity at its surface would be a.9.8 m/s2 b.107 dynes c.4.9 m/s2 d.19.6 m/s2 e.2.45 m/s2

Last Answer : d. 19.6 m/s2

A non-reversible machine has efficiency a.less than 50% b.nearly 100% c.between 75% and 99% d.more than 50% e.107 dynes

Description : A non-reversible machine has efficiency a.less than 50% b.nearly 100% c.between 75% and 99% d.more than 50% e.107 dynes

Last Answer : a. less than 50%

For a self locking lifting machine, the efficiency must be a.50 percent b.100 percent c.more than 50 percent d.107 dynes e.less than 50 percent

Description : For a self locking lifting machine, the efficiency must be a.50 percent b.100 percent c.more than 50 percent d.107 dynes e.less than 50 percent

Last Answer : e. less than 50 percent

In a single threaded worm and worm wheel the number of teeth on the worm wheel is 60. The diameter of the effort wheel is 12 cm and that of load drum is 8 cm. The velocity ratio will be a.90 b.120 c.60 d.45 e.107 dynes

Description : In a single threaded worm and worm wheel the number of teeth on the worm wheel is 60. The diameter of the effort wheel is 12 cm and that of load drum is 8 cm. The velocity ratio will be a.90 b.120 c.60 d.45 e.107 dynes

Last Answer : a. 90

In a single threaded worm and worm wheel the number of teeth on the worm wheel is 80. The diameter of the effort wheel is 12 cm and that of load drum is 8 cm. The velocity ratio will be a.60 b.45 c.120 d.107 dynes e.90

Description : In a single threaded worm and worm wheel the number of teeth on the worm wheel is 80. The diameter of the effort wheel is 12 cm and that of load drum is 8 cm. The velocity ratio will be a.60 b.45 c.120 d.107 dynes e.90

Last Answer : c. 120

The x coordinate of the centroid of the area enclosed by the parabolas y = x2 and x = y2 will be a.107 dynes b.0.44 c.0.43 d.0.45 e.0.46

Description : The x coordinate of the centroid of the area enclosed by the parabolas y = x2 and x = y2 will be a.107 dynes b.0.44 c.0.43 d.0.45 e.0.46

Last Answer : d. 0.45

An automobile is travelling at 25 m/s. It takes 0.3 second to apply the brakes after which the deceleration is 6 m/s2. How far, in meters, does the automobile travel before it stops? a.45 b.107 dynes c.40 d.50 e.60

Description : An automobile is travelling at 25 m/s. It takes 0.3 second to apply the brakes after which the deceleration is 6 m/s2. How far, in meters, does the automobile travel before it stops? a.45 b.107 dynes c.40 d.50 e.60

Last Answer : e. 60

A machine requires an effort of 10 kg to lift a load of 250 kg and an effort of 13 kg for a load of 400 kg. The effort required to lift a load of 500 kg will be a.25 kg b.107 dynes c.15 kg d.35 kg e.45 kg

Description : A machine requires an effort of 10 kg to lift a load of 250 kg and an effort of 13 kg for a load of 400 kg. The effort required to lift a load of 500 kg will be a.25 kg b.107 dynes c.15 kg d.35 kg e.45 kg

Last Answer : c. 15 kg

At a roller support the line of reaction and the roller base must be at an angle of a.60? b.90? c.not less than 60? d.not more than 60? e.107 dynes

Description : At a roller support the line of reaction and the roller base must be at an angle of a.60? b.90? c.not less than 60? d.not more than 60? e.107 dynes

Last Answer : b. 90?

TIES : STRUTS : a.purlins : piers b.angle : tee c.rolle support : hinge d.compression : tension e.107 dynes

Description : TIES : STRUTS : a.purlins : piers b.angle : tee c.rolle support : hinge d.compression : tension e.107 dynes

Last Answer : d. compression : tension

When two forces acting at a point are such that if the direction of one is reversed, the direction of the resultant is turned through a right angle, the forces must be a.inclined at more than 90? b.inclined at less than 90? c.equal in magnitude d.acting at 180? e.107 dynes

Description : When two forces acting at a point are such that if the direction of one is reversed, the direction of the resultant is turned through a right angle, the forces must be a.inclined at more than 90? b.inclined at less than 90? c.equal in magnitude d.acting at 180? e.107 dynes

Last Answer : c. equal in magnitude

A plane is inclinea at angle ? to horizontal. If a body can just rest on a plane, determine the least force to draw the body up the plance a.W sin2? b.2 W cos2? c.107 dynes d.W cos2? e.2 W sin2?

Description : A plane is inclinea at angle ? to horizontal. If a body can just rest on a plane, determine the least force to draw the body up the plance a.W sin2? b.2 W cos2? c.107 dynes d.W cos2? e.2 W sin2?

Last Answer : a. W sin2?

When two concurrent and coplaner forces P and Q act at an angle of 180?, their resultant will be a a.moment equal to PQ b.couple c.(P-Q) d.107 dynes e.zero

Description : When two concurrent and coplaner forces P and Q act at an angle of 180?, their resultant will be a a.moment equal to PQ b.couple c.(P-Q) d.107 dynes e.zero

Last Answer : c. (P-Q)

When horizontal range of a projectile equal to the distance through which projectile will rise, then the angle of projection of the particle will be equal to a.36? b.24? c.48? d.107 dynes e.76?

Description : When horizontal range of a projectile equal to the distance through which projectile will rise, then the angle of projection of the particle will be equal to a.36? b.24? c.48? d.107 dynes e.76?

Last Answer : e. 76?

The maximum efficiency of a scres jack having square threads and friction angle of 30 degree will be a.0.2 b.0.11 c.0.05 d.0.33 e.0.09

Description : The maximum efficiency of a scres jack having square threads and friction angle of 30 degree will be a.0.2 b.0.11 c.0.05 d.0.33 e.0.09

Last Answer : d. 0.33

According to principle of transmissiblity of forces, when a force acts upon a body, its effect is a.maximum when it acts at C.G. of the body b.minimum when it acts at C.G. of the body c.different at different points of the body d.107 dynes e.same at every point in its line of action

Description : According to principle of transmissiblity of forces, when a force acts upon a body, its effect is a.maximum when it acts at C.G. of the body b.minimum when it acts at C.G. of the body c.different at different points of the body d.107 dynes e.same at every point in its line of action

Last Answer : e. same at every point in its line of action

What is the maximum force, in Newtons, that will not cause tension? a.294 b.316 c.346 d.184 e.107 dynes

Description : What is the maximum force, in Newtons, that will not cause tension? a.294 b.316 c.346 d.184 e.107 dynes

Last Answer : a. 294

A body having SHM has period of 6 sec and amplitude of 4 mts. Maximum velocity is a.?/3 m/s b.2?/3 m/s c.107 dynes d.3? m/s e.4?/3 m/s

Description : A body having SHM has period of 6 sec and amplitude of 4 mts. Maximum velocity is a.?/3 m/s b.2?/3 m/s c.107 dynes d.3? m/s e.4?/3 m/s

Last Answer : e. 4?/3 m/s

A train travels between two stations 15 km apart in 18 minutes. If the train accelerates for a part of journey uniformly followed by uniform retardation, the maximum speed attained by the train during the journey will by a.125 km/hr b.107 dynes c.80 km/hr d.100 km/hr e.60 km/hr

Description : A train travels between two stations 15 km apart in 18 minutes. If the train accelerates for a part of journey uniformly followed by uniform retardation, the maximum speed attained by the train during the journey will by a.125 km/hr b.107 dynes c.80 km/hr d.100 km/hr e.60 km/hr

Last Answer : d. 100 km/hr

A train travels between two stations 15 km, apart in 18 minutes. If the train accelerates for a part of journey uniformly followed by uniform relardation, the maximum speed attained by the train, during, the journey, will be a.60 km/hr b.80 km/hr c.125 km/hr d.100 km/hr e.107 dynes

Description : A train travels between two stations 15 km, apart in 18 minutes. If the train accelerates for a part of journey uniformly followed by uniform relardation, the maximum speed attained by the train, during, the journey, will be a.60 km/hr b.80 km/hr c.125 km/hr d.100 km/hr e.107 dynes

Last Answer : d. 100 km/hr

A horizontal load of 120 kg/mt is to be carried by a cable suspended between supports at same level and 60 mts apart. If the maximum permissible tension is 36,000 kg the required length of cable is a.63.3 mets b.62.5 mts c.60.8 mts d.107 dynes e.60.1 mts

Description : A horizontal load of 120 kg/mt is to be carried by a cable suspended between supports at same level and 60 mts apart. If the maximum permissible tension is 36,000 kg the required length of cable is a.63.3 mets b.62.5 mts c.60.8 mts d.107 dynes e.60.1 mts

Last Answer : e. 60.1 mts

A boy sitting in a rail road car throws a ball straight up into the air. The ball will fall back into his hands when the rail road car is a.moving at constant velocity b.accelerating forward while going around a curve of radius equal to the maximum height attained by the ball c.107 dynes d.accelerating forwardA block A is dropped down a smooth inclined plane, while another identical block B is released for free fall from the same height e.decelerating

Description : A boy sitting in a rail road car throws a ball straight up into the air. The ball will fall back into his hands when the rail road car is a.moving at constant velocity b.accelerating ... inclined plane, while another identical block B is released for free fall from the same height e.decelerating

Last Answer : a. moving at constant velocity

The power of a locomotive is 315 kW and the total weight of the train is 2000 kN. If the track resistance is 15 N per kN, the maximum speed that the locomotive can attain on level track will be a.43 kmph b.83 kmph c.103 kmph d.107 dynes e.38 kmph

Description : The power of a locomotive is 315 kW and the total weight of the train is 2000 kN. If the track resistance is 15 N per kN, the maximum speed that the locomotive can attain on level track will be a.43 kmph b.83 kmph c.103 kmph d.107 dynes e.38 kmph

Last Answer : e. 38 kmph

Maximum acceleration in above problem is a.107 dynes b.2?2/3 m/s2 c.?2/s m/s2 d.3?2 m/s2 e.4?2/9 m/s2

Description : Maximum acceleration in above problem is a.107 dynes b.2?2/3 m/s2 c.?2/s m/s2 d.3?2 m/s2 e.4?2/9 m/s2

Last Answer : e. 4?2/9 m/s2

In case of cantilever, irrespective of the type of loading the maximum bendry moment and maximum shear force occur at a.107 dynes b.Free end c.2/3 of the length, from the free end d.Centre of the beam e.Fixed end

Description : In case of cantilever, irrespective of the type of loading the maximum bendry moment and maximum shear force occur at a.107 dynes b.Free end c.2/3 of the length, from the free end d.Centre of the beam e.Fixed end

Last Answer : e. Fixed end

The gravitational field intensity is maximum at the a.107 dynes b.at a height above the surface c.pole d.equator e.centre of the earth

Description : The gravitational field intensity is maximum at the a.107 dynes b.at a height above the surface c.pole d.equator e.centre of the earth

Last Answer : e. centre of the earth

The power of a locomotive is 315 kW and the total weight of the train is 2000 kN. If the track resistance is qN per kN, the maximum speed that the locomotive can attain on level track will be a.103 kmph b.83 kmph c.107 dynes d.43 kmph e.63 kmph

Description : The power of a locomotive is 315 kW and the total weight of the train is 2000 kN. If the track resistance is qN per kN, the maximum speed that the locomotive can attain on level track will be a.103 kmph b.83 kmph c.107 dynes d.43 kmph e.63 kmph

Last Answer : e. 63 kmph

A particle in SHM while passing through mean position will have a.maximum kinetic energy and maximum potential energy b.107 dynes c.maximum kinetic energy and minimum potential energy d.average kinetic energy and average potential energy. e.minimum kinetic energy and maximum potential energy

Description : A particle in SHM while passing through mean position will have a.maximum kinetic energy and maximum potential energy b.107 dynes c.maximum kinetic energy and minimum potential energy d.average kinetic energy and average potential energy. e.minimum kinetic energy and maximum potential energy

Last Answer : c. maximum kinetic energy and minimum potential energy

A cable is supported at A and B, in which B is higher than A. The tension in the cable will be maximum at a.A b.A and B c.C d.B e.107 dynes

Description : A cable is supported at A and B, in which B is higher than A. The tension in the cable will be maximum at a.A b.A and B c.C d.B e.107 dynes

Last Answer : d. B

Rain drops (assumed to be spherical) of radii R1, 2R1, 3R, 4R, a.all of them will be zero b.all of them will be same c.drops of radius R will be maximum d.drops of radius R will be minimum e.107 dynes

Description : Rain drops (assumed to be spherical) of radii R1, 2R1, 3R, 4R, a.all of them will be zero b.all of them will be same c.drops of radius R will be maximum d.drops of radius R will be minimum e.107 dynes

Last Answer : d. drops of radius R will be minimum

A man is standing near the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platform will decrease if he a.extends his arms outwards b.moves towards the axis of rotation c.jumps out from the platform d.accepts a heavy bag from one of his friends standing near by and holds it in his hand e.107 dynes

Description : A man is standing near the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platform will decrease if he a.extends his arms outwards b.moves ... heavy bag from one of his friends standing near by and holds it in his hand e.107 dynes

Last Answer : d. accepts a heavy bag from one of his friends standing near by and holds it in his hand

A man is standing ner the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platorm will decrease if he a.extends his arms outwards b.107 dynes c.moves towards the axis of rotation d.jumps out from that platform e.take out his coat and throws away

Description : A man is standing ner the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platorm will decrease if he a.extends his arms outwards b.107 ... towards the axis of rotation d.jumps out from that platform e.take out his coat and throws away

Last Answer : a. extends his arms outwards

The mass, in kg, of the earth if its radius is 6400 km, will be a.6 x 1024 b.6 x 1025 c.107 dynes d.6 x 1023 e.6 x 1022

Description : The mass, in kg, of the earth if its radius is 6400 km, will be a.6 x 1024 b.6 x 1025 c.107 dynes d.6 x 1023 e.6 x 1022

Last Answer : a. 6 x 1024

A wheel 8 mts in diameter coasts to rest from a speed of 800 rpm in 10 minutes. Its angular deceleration is a.308/min2 b.683 rad/min2 c.502 rad/min2 d.107 dynes e.809 rad/min2

Description : A wheel 8 mts in diameter coasts to rest from a speed of 800 rpm in 10 minutes. Its angular deceleration is a.308/min2 b.683 rad/min2 c.502 rad/min2 d.107 dynes e.809 rad/min2

Last Answer : c. 502 rad/min2

If a particle charges its angular velocity from 30 to 35 rpm in 20 seconds then it has angular acceleration of a.107 dynes b.30 rev/min2 c.10 rev/min2 d.20 rev/min2 e.15 rev/min2

Description : If a particle charges its angular velocity from 30 to 35 rpm in 20 seconds then it has angular acceleration of a.107 dynes b.30 rev/min2 c.10 rev/min2 d.20 rev/min2 e.15 rev/min2

Last Answer : e. 15 rev/min2

Under which circumstances will have zero velocity and be still accelerating? a.The bob of a simple pendulum when at its mean position b.107 dynes c.A steamer while taking a turn d.A ball at its highest point of its rise when thrown up e.Tyres of a stationary automobile

Description : Under which circumstances will have zero velocity and be still accelerating? a.The bob of a simple pendulum when at its mean position b.107 dynes c.A steamer while taking a turn d.A ball at its highest point of its rise when thrown up e.Tyres of a stationary automobile

Last Answer : d. A ball at its highest point of its rise when thrown up

A column has its equivalent length equal to its length in case of a.one end fixed, other free b.both ends hinged c.one end hinged, other free d.107 dynes e.both end fixed

Description : A column has its equivalent length equal to its length in case of a.one end fixed, other free b.both ends hinged c.one end hinged, other free d.107 dynes e.both end fixed

Last Answer : b. both ends hinged

A force F = 2i + 3j - k is passing through the origin. Its moment about point (1, 1, 0) is a.107 dynes b.i + j + k c.2i + 3j d.zero e.i - j - k

Description : A force F = 2i + 3j - k is passing through the origin. Its moment about point (1, 1, 0) is a.107 dynes b.i + j + k c.2i + 3j d.zero e.i - j - k

Last Answer : b. i + j + k

If a solid sphere rolls on a horizontal surface, then the ratio of its rotational kinetic energy to its total kinetic energy is a.1 ; 7 b.3 ; 7 c.107 dynes d.4 ; 7 e.2 ; 7

Description : If a solid sphere rolls on a horizontal surface, then the ratio of its rotational kinetic energy to its total kinetic energy is a.1 ; 7 b.3 ; 7 c.107 dynes d.4 ; 7 e.2 ; 7

Last Answer : e. 2 ; 7

A 100 kg flywheel having a radius of gyration of 1 m is rotating at 1000 rpm. The angular momentum of the flywheel about its axis of rotation, in kg m2/s is a.1000 b.107 dynes c.10000 d.10470 e.5235

Description : A 100 kg flywheel having a radius of gyration of 1 m is rotating at 1000 rpm. The angular momentum of the flywheel about its axis of rotation, in kg m2/s is a.1000 b.107 dynes c.10000 d.10470 e.5235

Last Answer : d. 10470

A grinding wheel rotates at 3000 rpm. When power supply is cut off the wheel stops in 5 sec. The number of revolutions made by the wheel before coming to rest would be a.500 b.107 dynes c.250 d.3000 e.1000

Description : A grinding wheel rotates at 3000 rpm. When power supply is cut off the wheel stops in 5 sec. The number of revolutions made by the wheel before coming to rest would be a.500 b.107 dynes c.250 d.3000 e.1000

Last Answer : c. 250

What force is necessary to hold a weight of 100 kg suspended on a rope wrapped 3 times around a post ( a.0.35 b.0.8 c.1.46 d.2.85 e.107 dynes

Description : What force is necessary to hold a weight of 100 kg suspended on a rope wrapped 3 times around a post ( a.0.35 b.0.8 c.1.46 d.2.85 e.107 dynes

Last Answer : a. 0.35

A projectile is shot straight up with vo = 40 m/s. After how many seconds will it return if drag is neglected? a.6 b.107 dynes c.4 d.10 e.8

Description : A projectile is shot straight up with vo = 40 m/s. After how many seconds will it return if drag is neglected? a.6 b.107 dynes c.4 d.10 e.8

Last Answer : e. 8

A block A is dropped down a smooth inclined plane, while another identical block B is released for free fall from the same height a.block A will have higher velocity than block B while hitting the ground b.block B will hit the ground earlier. c.both will hit the ground simultaneously d.block A will hit the ground earlier e.107 dynes

Description : A block A is dropped down a smooth inclined plane, while another identical block B is released for free fall from the same height a.block A will have higher velocity than block B while hitting the ... . c.both will hit the ground simultaneously d.block A will hit the ground earlier e.107 dynes

Last Answer : b. block B will hit the ground earlier.

An automobile weighing 2800 lb and travelling at 30 miles/hr, hits a depression in the road which has a radius of curvature of 50 ft. What is the total force to which springs are subjected. a.8230 lb b.6170 lb c.2800 ib d.107 dynes e.3280 lb

Description : An automobile weighing 2800 lb and travelling at 30 miles/hr, hits a depression in the road which has a radius of curvature of 50 ft. What is the total force to which springs are subjected. a.8230 lb b.6170 lb c.2800 ib d.107 dynes e.3280 lb

Last Answer : b. 6170 lb

A ball A of mass 0.25 kg moving on a smooth horizontal table with a velocity of 10 m/s strikes an identical stationary ball B on the table. If the impact is perfectly elastic, the velocity of the ball B just after the impact will be a.2.5 m/s b.zero c.5 m/s d.10 m/s e.107 dynes

Description : A ball A of mass 0.25 kg moving on a smooth horizontal table with a velocity of 10 m/s strikes an identical stationary ball B on the table. If the impact is perfectly elastic, the velocity of the ball B just after the impact will be a.2.5 m/s b.zero c.5 m/s d.10 m/s e.107 dynes

Last Answer : c. 5 m/s

A stone weighing 20 N is whirling in a vertical circle at the extremity of a string 100 cm long. The tension in the string will be zero a.at the highest position b.at the lowest position c.at the midway position d.at none of the above e.107 dynes

Description : A stone weighing 20 N is whirling in a vertical circle at the extremity of a string 100 cm long. The tension in the string will be zero a.at the highest position b.at the lowest position c.at the midway position d.at none of the above e.107 dynes

Last Answer : a. at the highest position

If the distance to electric train is given by Fr = a + bv + cv2 In this equation constant c is likely to cover a.air resistance b.track resistance c.frictional resistance d.flange resistance e.107 dynes

Description : If the distance to electric train is given by Fr = a + bv + cv2 In this equation constant c is likely to cover a.air resistance b.track resistance c.frictional resistance d.flange resistance e.107 dynes

Last Answer : a. air resistance