**
When the crank is at the inner dead centre, in a reciprocating steam engine, then the velocity of the piston will be**

**(A)**minimum

**(B)**zero

**(C)**maximum

**(D)**none of these

**B**

**
The unbalanced primary forces in a reciprocating engine are**

**(A)**balanced partially

**(B)**balanced completely

**(C)**balanced by secondary forces

**(D)**not balanced

**A**

**
If the mass of the reciprocating parts is doubled, then the primary force is halved.**

**(A)**True

**(B)**False

**B**

**
In order to balance the reciprocating masses,**

**(A)**primary forces and couples must be balanced

**(B)**secondary forces and couples must be balanced

**(C)**both (a) and (b)

**(D)**none of these

**C**

**
The acceleration of piston in a reciprocating steam engine is given by (where $\omega $ = Angular velocity of a crank, r = Radius of crankpin circle, $\theta $ = Angle turned by a crank from inner dead centre, and n = Ratio of length of connecting rod to the radius of a crank)**

**(A)**$r.\omega \left(\mathrm{sin}\theta +\frac{\mathrm{sin}2\theta}{n}\right)$

**(B)**$r.\omega \left(\mathrm{cos}\theta +\frac{\mathrm{cos}2\theta}{n}\right)$

**(C)**$r.{\omega}^{2}\left(\mathrm{sin}\theta +\frac{\mathrm{sin}2\theta}{n}\right)$

**(D)**$r.{\omega}^{2}\left(\mathrm{cos}\theta +\frac{\mathrm{cos}2\theta}{n}\right)$

**D**