## Engineering Mechanics Practice Questions (Mechanical) Set 1

##### After compression, the time taken by the bodies to regain original shape is known as

Options are :

• Time of collision
• Time of compression
• None of these
• Time of restitution

##### In a simple gear train, the motion of driven gear will .if the number of idle gear is odd

Options are :

• Be opposite as that of driving gear
• Depend upon the number of teeth on the driving gear
• Be same as that of driving gear
• None of these

Answer : Be same as that of driving gear

Options are :

• g/4
• g/3
• g/2
• g

##### In cross belt drives the power is transmitted between pulleys rotating in

Options are :

• Either of these
• Opposite direction
• Same direction
• None of these

##### The co-efficient of friction between two surfaces is the constant of proportionality between the applied tangential force and the normal reaction at

Options are :

• Any instant after the motion takes place
• The instant of the application of the force
• The instant of impending motion
• Any instant when the body is at rest

Answer : The instant of impending motion

Options are :

• 750 mm
• 1114 mm
• 994 mm
• 550 mm

##### The co-efficient of restitution is defined on the basis of which parameters?

Options are :

• Velocity components along the line of impact only
• Velocity components normal to the line of impact
• Velocity vectors before and after the impact
• All of these

Answer : Velocity components along the line of impact only

##### In case of motion of two bodies (W1 > W2) connected by a string passing over a smooth pulley, the tension (T) in the string is given by

Options are :

• 2W1 W2/ W1 + W2
• W1 W2/ W1 + W2
• 4W1 W2/ W1 + W2
• 3W1 W2/ W1 + W2

Answer : 2W1 W2/ W1 + W2

##### Number of teeth on a wheel per unit of its pitch diameter is called

Options are :

• None of these
• Diametral pitch
• Module
• Circular pitch

##### When the distance between the shaft centres is belts and ropes are used

Options are :

• Large
• Very small
• Small
• None of these

##### Equation of a trajectory is written as

Options are :

• y = x tan a + gx^(2)/2u^(2)cos^(2)?
• y = x2 tan ? - gx^(2)/2u^(2)cos^(2)?
• y = x cos ? gx^(2)/2u^(2)cos^(2)?
• y = x tan a - gx^(2)/2u^(2)cos^(2)?

Answer : y = x tan a - gx^(2)/2u^(2)cos^(2)?

##### Time of flight of a projectile is given by

Options are :

• u^2 sin?/g
• u sin?/g
• 2u sin^(2)?/g
• 2u sin?/g

##### In a combined motion of translation and rotation

Options are :

• None of these
• The motion of translation takes place before the motion of rotation
• The motion of rotation takes place before the motion of translation
• Both the motions take place simultaneously

Answer : Both the motions take place simultaneously

Options are :

• ?= ?/2
• ?=2 ?
• ?= ?
• ?= ?^2

##### In a screw jack the effort (P) required to lift the load (W) is given by the relation

Options are :

• P=W tan (?2+ ?)
• P=W tan (?+ ?)
• P=W tan (?- ?)
• P=W tan (? 2- ?)

Answer : P=W tan (?+ ?)

##### The condition for maximum efficiency in case of a screw is given by

Options are :

• ? = 45ฐ - (?/2)
• ? = 45ฐ + (?/2)
• ? = 60ฐ - (?/2)
• ? = 60ฐ + (?/2)

Answer : ? = 45ฐ - (?/2)

##### 'The algebraic sum of the moments of two forces about any point in their plane is equal to the moment of their resultant about that point'. The above statement is called

Options are :

• Varignon's theorem
• Principles of moments
• Theorem of perpendicular axes
• Theorem of parallel axes

##### The resultant of two forces P and Q acting at an angle is

Options are :

• ?P2 + Q2 + 2PQcos?
• ?P2 + Q2 - PQcos?
• ?P2 + Q2 + PQcos?
• ?P2 - Q2 + PQcos?

Answer : ?P2 + Q2 + 2PQcos?

##### Range of a projectile is given by

Options are :

• u^2 sin^(2)(?)/g
• u^2 sin (2?)/g
• u^3 sin (?)/g
• u sin^(2) (?)/2g

##### A free body diagram of a body shows a body

Options are :

• With its surroundings and external forces acting on it
• Isolated from its surroundings and all external actions on it
• Isolated from all external actions
• None of these

Answer : Isolated from its surroundings and all external actions on it

##### Number of teeth on a wheel per unit of its pitch diameter is called

Options are :

• Module
• Circular pitch
• None of these
• Diametral pitch

##### In a simple gear train, the motion of driven gear will .if the number of idle gear is odd

Options are :

• Be opposite as that of driving gear
• None of these
• Be same as that of driving gear
• Depend upon the number of teeth on the driving gear

Answer : Be same as that of driving gear

Options are :

• 994 mm
• 1114 mm
• 550 mm
• 750 mm

##### In cross belt drives the power is transmitted between pulleys rotating in

Options are :

• Same direction
• Either of these
• None of these
• Opposite direction

##### The co-efficient of restitution is defined on the basis of which parameters?

Options are :

• Velocity components along the line of impact only
• All of these
• Velocity vectors before and after the impact
• Velocity components normal to the line of impact

Answer : Velocity components along the line of impact only

##### After compression, the time taken by the bodies to regain original shape is known as

Options are :

• Time of collision
• Time of restitution
• None of these
• Time of compression

Options are :

• g
• g/3
• g/2
• g/4

##### In case of motion of two bodies (W1 > W2) connected by a string passing over a smooth pulley, the tension (T) in the string is given by

Options are :

• 2W1 W2/ W1 + W2
• W1 W2/ W1 + W2
• 4W1 W2/ W1 + W2
• 3W1 W2/ W1 + W2

Answer : 2W1 W2/ W1 + W2

##### When the distance between the shaft centres is belts and ropes are used

Options are :

• Small
• None of these
• Very small
• Large

##### The co-efficient of friction between two surfaces is the constant of proportionality between the applied tangential force and the normal reaction at

Options are :

• Any instant when the body is at rest
• The instant of impending motion
• The instant of the application of the force
• Any instant after the motion takes place

Answer : The instant of impending motion