JULY 2018 MACHINIST THEORY SEMESTER – IV ITI MCQ


JULY 2018 MACHINIST  THEORY  SEMESTER – IV

To increase the_rates a higher cutting speed and feed is used in CNC machines.
(a) Cutting
(b) Moving
(c) Shaking
(d) Rotating
Answer: (a) Cutting


Two basic type of tooling in NC turning machines are qualified tooling and_tooling.
(a) Advanced
(b) Basic
(c) Universal
(d) General
Answer: (b) Basic


In CNC machines tool changing time is_to increase the production of
components.
(a) Reduced
(b) Increased
(c) Kept same
(d) None of these
Answer: (a) Reduced


Manual part programming requires a/an_programmer.
(a) Expert
(b) Unskilled
(c) Trained
(d) All of these
Answer: (a) Expert


In motion statement, GOTO and GO/TO are
(a) Do not exist      
(b) Not required    '  
(c) Same
(d) Different
Answer: (d) Different


In CNC machines_type of tool changer is used with either side mounted or
back mounted tool magazines.
(a) Pivot insertion
(b) Multi-axis
(c) Turret head
(d) Automatic tool changer
Answer: (b) Multi-axis


The type of tool magazines used in CNC machines are: -
(a) Drum .
(b) Chain
(c) Egg box
(d) All of these
Answer: (d) All of these



In case of tool changer for CNC machines ATC means
(a) Anti Tool Changer
(b) Automatic Tool Changer
(c) Automatic turret changer
(d) None of these
Answer: (b) Automatic Tool Changer

In CNC lathe machine turret heads are available holding upto …… tools.
(a) 24
(b) 08
(c) 12
(d) 02
Answer: (c) 12


The advantage of ceramic cutting tool is: -
(a) Higher cutting speed
(b) Longer Tool life
(c) Reduced Built-up edge
(d) All of these
Answer: (d) All of these


The main characteristic of ceramic cutting tool is: -
(a) High compressive strength
(b) High tensile strength
(c) Low brittleness
(d) Cannot be operated on high speeds
Answer: (a) High compressive strength


Which among the following causes first order surface irregularity?
(a) Lack of straightness
(b) Lack of rigidity
(c) Feed and speed
(d) Vibrations
Answer: (a) Lack of straightness

The surface roughness on a drawing is represented by: -
(a) Circle
(b) Square
(c) Zig-zag lines      
(d) Triangle
Answer: (d) Triangle


Select the milling machine most suitable for helical gear cutting:
(a) Plain milling machine
(b) Hand milling machine
(c) Universal milling machine
(d) None of these
Answer: (c) Universal milling machine


The worm wheel have gear teeth like: -
(a) Spur gear
(b) Helical gear       
(c) Bevel gear
(d) None of these
Answer: (a) Spur gear


Worm gears are used when_gear reductions are needed.
(a) Small
(b) Large
(c) No
(d) None of these
Answer: (b) Large


Worm gears are used for transmitting power between
(a) Two non-parallel, non-intersecting
(b) Two parallel, non-intersecting shafts
(c) Both (a)& (b)
(d) None of these
Answer: (a) Two non-parallel, non-intersecting

The geometry of a worm gear is similar to that of a__gear.
(a) Spur gear
(b) Helical gear       
(c) Bevel gear
(d) None of these
Answer: (b) Helical gear       

Rack is a segment of a gear of_diameter.
(a) Small
(b) Very small
(c) Infinite
(d) None of these
Answer: (c) Infinite


The type of gearing is used for converting rotary motion into translatory motion or vice
versa is: -
(a) Rack and pinion  
(b) Bevel gear       
(c) Spur gear
(d) None of these
Answer: (a) Rack and pinion  


In general longest rack can be made by using
(a) Lathe
(b) Shaper
(c) Horizontal milling machine
(d) Planer
Answer: (c) Horizontal milling machine

The module of a gear is given by(Where d=diameter of pitch circle, t=number of teeth)
(a)  d/t
(b)  d/2t
(c)  2d/t
(d)  d/3t
Answer: (a)  d/t


The minimum number of teeth on pinion to avoid interference in rack and pinion is: -
(a)   15
(b)  18
(c)  21
(d)  24
Answer: (b)  18


In worm and wheel, the shaft axes are at: -
(a)  90°
(b)  45°
(c) 180°
(d)  270°
Answer: (a)  90°

In single started worm, for one rotation, the wheel will rotate equal to; -
(a)  p/2
(b)  p  
(c)  2p
(d)  p/3
Answer: (b)  p  

The included angle of live centre nose is: -
(a) 30°
(b) 45°
(c) 60°
(d) 90°
Answer: (c) 60°

The gears are used to connect two parallel shafts except: -
(a) Spur gear
(b) Helical gear      
(c) Bevel gear
(d) None of these
Answer: (c) Bevel gear


On the basis of shapes, the cam can be: -
(a) Radial or disc cam
(b) Cylindrical cam  
(c) Translating cam  
(d) All of these
Answer: (d) All of these

A cam basically imparts the following motions: -
(a) Rotating
(b) Oscillating
(c) Reciprocating      
(d) All of these
Answer: (d) All of these


Involute profile is preferred to cyloidal because: -
(a) The profile is easy to cut
(b) only one curve is required to cut
(c) The rack has straight line profile and hence can be cut accurately
(d) None of the above
Answer: (b) only one curve is required to cut

The product of the diametral pitch and circular pitch is equal to: -
(a)  l
(b)  l/π      
(c)  π           
(d)  2π
Answer: (c)  π           

The size of a gear is usually specified by: -
(a) Pressure angle
(b) Circular pitch
(c) Diametral pitch
(d) Pitch circle diameter
Answer: (d) Pitch circle diameter

Internal gears and splines used in automobile industry are manufactured by: -
(a) Casting
(b) Milling
(c) Broaching
(d) Gear shaping
Answer: (c) Broaching

Gear cutter No. 1 for cutting gears on milling machine is used for: -
(a) Racks only
(b) 12 to 13 teeth     
(c) 17 to 20 teeth     
(d) 135 to 150 teeth
Answer: (d) 135 to 150 teeth

Kerosene is used as a cutting fluid while machining: -
(a) Aluminium       
(b) Magnesium       
(c) Brass
(d) Low carbon steel
Answer: (a) Aluminium       

A lubricant is used primarily to prevent: -
(a) Corrosion of metals
(b) Oxidation of metal
(c) Wearing out of rubbing metallic surface
(d) Reduction of metals
Answer: (c) Wearing out of rubbing metallic surface
Broaching is primarily done for: -
(a) Better finish      
(b) Mass production
(c) Cylindrical jobs  
(d) Hard materials
Answer: (b) Mass production

The feed depends on:
(a) Finish required   
(b) Depth of cut      
(c) Rigidity of machine
(d) All of these
Answer: (d) All of these

Series of instructions used by CNC machine for their operation are
(a) Hardware
(b) Software
(c) Interface
(d) GUI
Answer: (b) Software

A series of instructions describing the part to be produced in an acceptable form to the
control unit or computer is known as_.
(a) GUI
(b) Part program     
(c) Output
(d) None of these
Answer: (b) Part program

G05 code stands for: -
(a) DWELL
(b) HOLD
(c) TAPPING
(d) CHANGE OF RATE
Answer: (b) HOLD

MOO code in part programming stands for: -
(a) End of programme
(b) Programme stop
(c) End of tape
(d) Clamp slide
Answer: (b) Programme stop

This prepares the CNC machine to perform a particular function: -
(a) Feed rate
(b) Preparatory function
(c) Speed rate
(d) Tool rate
Answer: (b) Preparatory function

G82 means: -
(a) DWELL
(b) CENTRE DRILLING
(c) TAPPING
(d) TOOL NUMBER 82
Answer: (b) CENTRE DRILLING

Block number / sequence numbers are denoted by: -
(a) N words
(b) G words
(c) T words
(d) S words
Answer: (a) N words


When a motor is used in a position or speed control applications with sensor feedback to
controller, it is referred to as_.
(a) Motor
(b) Stepper motor    
(c) Servomotor       
(d) Resolvers
Answer: (c) Servomotor       


In place of leadscrew CNC uses a: -
(a) Synchro connection
(b) Circulating lead screw
(c) Circulating ball screw and nut assembly
(d) None of these
Answer: (c) Circulating ball screw and nut assembly

The cutting tool used on the basis of construction in CNC machines are: -
(a) Solid tools
(b) Brazed tools      
(c) Inserted bit tools 
(d) All of these
Answer: (d) All of these

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