Zero Force Members in a Truss

Q. The members carrying zero force (i.e. zero -force members) in truss shown in the figure, for any load P > 0 with no appreciable deformation of the truss (i.e with no appreciable change in angles between the members), are

1. BF, DH and GC only

2. BF, DH, GC, CD and DE only

3. BF and DH only

4. BF, DH, GC, FG and GH only

Q. The figure shows a pin-jointed plane truss loaded at the point M by hanging a mass of 100 kg. The member LN of the truss is subjected to a load of

1. 0 Newton
2. 490 Newtons in Compression
3. 981 Newtons in Compression
4. 981 Newtons in tension