Related Questions

The cutting speed for drilling aluminium, brass and bronze with carbon steel drills is _________ cutting speed for drilling mild steel with high speed steel drills.
A Equal to
B Less than
C More than
D None of these
High speed steel drills can be operated at about _________ the speed of high carbon steel drills.
A One-half
B One-fourth
C Double
D Four times
The cutting speed for drilling aluminium, brass and bronze with high speed steel drills varies from
A 10 to 20 m/min
B 18 to 30 m/min
C 24 to 45 m/min
D 60 to 90 m/min
The cutting speed for drilling copper with high speed steel drills varies from
A 10 to 20 m/min
B 18 to 30 m/min
C 24 to 45 m/min
D 60 to 90 m/min
The helix angle of a drill is __________ for drilling brass.
A Equal to 30°
B Less than 30°
C More than 30°
D None of these
The correct sequence of drilling equipment for increasing size of holes in tunnels is
A Wagon drill, churn drill, shot drill
B Wagon drill, shot drill, churn drill
C Shot drill, churn drill, wagon drill
D Churn drill, wagon drill, shot drill
What does the underlined word mean in the following sentence?The old man's house, badly in need of paint, was leaning to one side and had holes in the roof, but one side and had holes in the roof, but
A poorly built
B old-fashioned
C run down
D dirty
An intrinsic semiconductor has some holes in it at room temperature. What causes these holes?
A Doping
B Valence electrons
C Free electrons
D Thermal energy
E None of the above
In order to ensure self locking in a screw jack, it is essential that helix angle is __________ friction angle.
A Larger than
B Smaller than
C Equal to
D None of these
In a screw jack, the effort required to lift the load W is given by (where $$\alpha $$ = Helix angle and $$\varphi $$ = Angle of friction)
A $${\text{P}} = {\text{W}}\tan \left( {\alpha - \varphi } \right)$$
B $${\text{P}} = {\text{W}}\tan \left( {\alpha + \varphi } \right)$$
C $${\text{P}} = {\text{W}}\tan \left( {\varphi - \alpha } \right)$$
D $${\text{P}} = {\text{W}}\cos \left( {\alpha + \varphi } \right)$$

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