Question

A plane truss has four members and four joints. The truss is

• A. Perfect
• B. Deficient
• C. Redundant
• D. Rigid

Hint:

Use the relation \( m = 2j - 3 \) to determine the type of truss: - If \( m = 2j - 3 \), it is perfect. - If \( m<2j - 3 \), it is deficient. - If \( m>2j - 3 \), it is redundant.

Answer 1

The Correct Option is B

Step 1: Use the truss member relation formula.
For a plane truss: \[ m = 2j - 3 \] where \( m \) is the number of members and \( j \) is the number of joints. Step 2: Substitute given values.
Given: \( m = 4 \), \( j = 4 \), \[ 2j - 3 = 2(4) - 3 = 5 \] But actual number of members = 4, which is less than 5. Hence, the truss is deficient.