Q1: A singly reinforced beam has breadth b, effective depth d, depth of neutral axis n and critical neutral axis n₁. If f_c and f_t are permissible compressive and tensile stresses, the moment to resistance of the beam, is

ANS:D - all the above

The moment of resistance of a singly reinforced beam can be calculated using the formula for flexural strength. Flexural strength, also known as moment capacity, is the maximum moment that the beam can resist before it reaches its failure state. The formula for the moment of resistance (Mr​) of a singly reinforced beam is given by: Mr​=ft​×As​×(d−As/2​​) Where:

• ft​ = Permissible tensile stress in the reinforcement (kg/cm²)
• As​ = Area of steel reinforcement (cm²)
• d = Effective depth of the beam (cm)

In this formula, As​ is the area of steel reinforcement, which is typically calculated using the formula: As​=π×ϕ/4​×n Where:

• ϕ = Diameter of the reinforcement bars (cm)
• n = Number of reinforcement bars

The depth of the neutral axis (n) is the distance from the compression face of the beam to the neutral axis, while the depth of the critical neutral axis (n1​) is the depth of the neutral axis when the beam reaches its failure state. Once the area of steel reinforcement (As​) is calculated, it can be substituted into the formula for Mr​ along with the other given parameters (ft​, d) to determine the moment of resistance of the beam. It's important to note that the permissible compressive stress (fc​) is not directly used in the calculation of the moment of resistance for a singly reinforced beam, as the beam primarily fails due to tensile stresses in the concrete or steel reinforcement. If you have specific values for ft​, d, n, 1n1​, and other relevant parameters, I can assist you further in calculating the moment of resistance of the beam.