Test: Method Of Joints - Civil Engineering (CE) MCQ

If the whole truss is in equilibrium then all the joints which are connected to that truss is in equilibrium. This is known as method of joints. This is one of the methods to solve for the forces which are acting along the trusses.

The direction of the unknown is not known to us. To know the direction of the unknown force we take assumption of it. That is we assume that the particular direction might be the direction of the force and then we do the calculations accordingly. And then we apply the equilibrium equations to the joints.

The free body diagram of joints part of the section of the truss is made to make use of method of joints. Various equations of equilibrium are made to do the calculations. The net force acting on the vertical direction is made zero. Also horizontal direction forces are made to be zero.

The forces are coplanar that’s why they are there in the calculations in the method of joints. The forces are resolved in 2D. This makes the condition of the equilibrium fulfilled and hence the method of joints uses the forces in the same plane for its calculation.

The forces are concurrent that’s why they are there in the calculations in the method of joints. The forces are resolved in 2D. This makes the condition of the equilibrium fulfilled by cancelling of various force members and hence the method of joints uses the concurrent forces for its calculation.

The direction of the unknown is not known to us. To know the direction of the unknown force we take assumption of it. That is we assume that the particular direction might be the direction of the force and then we do the calculations accordingly. And then we apply the equilibrium equations to the joints.

This makes the calculations easy. Also for the solving of any equation one requires equal number of variables as that of equal number of equation. So to do the calculations easily the above mentioned conditions are followed.

We use this method for the simplification of the forces in the sections of the structure. Not the entire structure. This means that the statement given is wrong. It should be the joints not the whole structure.

The direction of the unknown is not known to us. To know the direction of the unknown force we take assumption of it. That is we assume that the particular direction might be the direction of the force and then we do the calculations accordingly.

The first part is wrong. We can determine the magnitude of the unknown force. It can be done by using the equilibrium equations. That equating the forces zero, of the three different axis. Thus making the components of the unknown founded out.

The direction of the unknown is not known to us. To know the direction of the unknown force we take assumption of it. That is we assume that the particular direction might be the direction of the force and then we do the calculations accordingly. And then we apply the equilibrium equations to the joints.

The direction is comes opposite, means that the assumption was wrong. But that doesn’t means that the question can’t be solved further. One needs to change the sign of the direction and the question is solved. Thus the calculations of the force direction.

As one can imagine three vectors coming out of a single point and are having a 120 degree angle with their adjacent ones, the resultant would be zero.

Yes, the magnitude of the resultant of the two vectors always depends on the angle between them. It might be greater or smaller than one of the vector’s length. For perfectly saying, it does depends upon the angle between them.

The direction of the unknown is not known to us. To know the direction of the unknown force we take assumption of it. That is we assume that the particular direction might be the direction of the force and then we do the calculations accordingly. And then we apply the equilibrium equations to the joints.