Theory of Machine The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction) α = 45° + φ/2 α = 90° + φ α = 45° - φ/2 α = 90° - φ α = 45° + φ/2 α = 90° + φ α = 45° - φ/2 α = 90° - φ ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine The ratio of height of Porter governor (when length of arms and links are equal) to the height of Watt's governor is (where m = Mass of the ball, and M = Mass on the sleeve) (m + M)/M M/(m + M) (m + M)/m m/(m + M) (m + M)/M M/(m + M) (m + M)/m m/(m + M) ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine A rigid body possesses ________degrees of freedom Four Six Two One Four Six Two One ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine The example of rolling pair is Ball and socket joint Lead screw of a lathe Bolt and nut Ball bearing and roller bearing Ball and socket joint Lead screw of a lathe Bolt and nut Ball bearing and roller bearing ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine The two elements of a pair are said to form a higher pair, when they Are kept in contact by the action of external forces, when in motion Have a surface contact when in motion Permit relative motion Have a line or point contact when in motion Are kept in contact by the action of external forces, when in motion Have a surface contact when in motion Permit relative motion Have a line or point contact when in motion ANSWER DOWNLOAD EXAMIANS APP
Theory of Machine The secondary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, θ = Angle of inclination of crank with the line of stroke, and n = Ratio of the length of connecting rod to radius of crank) m.ω².r sinθ m.ω².r (sin 2θ/n) m.ω².r cosθ m.ω².r (cos 2θ/n) m.ω².r sinθ m.ω².r (sin 2θ/n) m.ω².r cosθ m.ω².r (cos 2θ/n) ANSWER DOWNLOAD EXAMIANS APP