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