Higher pair
Rolling pair
Sliding pair
Lower pair

L + 2
L - 1
L
L + 1

## Theory of Machine A Hartnell governor has its controlling force (Fc) given by Fc = ar + b, where r is the radius of rotation and a and b are constants. The governor becomes isochronous when

a is +ve and b is -ve
a is +ve and b = 0
a = 0 and b is +ve
a is +ve and b is also +ve

## Theory of Machine In a four-bar chain it is required to give an oscillatory motion to the follower for a continuous rotation of the crank. For the lengths of 50 mm of crank and 70 mm of the follower, determine theoretical maximum length of coupler. The distance between fixed pivots of crank and followers is

95 mm
45 mm
Slightly more than 95 mm
Slightly less than 95 mm

## Theory of Machine Which of the following is false statement in respect of differences between machine and structure?

In machines, relative motion exists between its members, whereas same does not exist in case of structures
Efficiency of machines as well as structures is below 100 %
Machines transmit mechanical work, whereas structures transmit forces
Machines modify movement and work, whereas structures modify forces