The correct answer is B. 0.50.
The ratio of the breadth to effective depth of a beam is kept at 0.50 to ensure that the beam is safe and does not fail. A lower ratio would make the beam more susceptible to bending, while a higher ratio would make the beam more susceptible to buckling.
The effective depth of a beam is the distance from the top of the beam to the neutral axis. The neutral axis is the imaginary line in the beam where there is no tension or compression. The breadth of a beam is the width of the beam.
The ratio of the breadth to effective depth of a beam is calculated using the following formula:
b/d = 0.50
where:
b = breadth of the beam
d = effective depth of the beam
The ratio of the breadth to effective depth of a beam is an important factor in determining the strength of a beam. A lower ratio will make the beam more susceptible to bending, while a higher ratio will make the beam more susceptible to buckling. It is important to keep the ratio of the breadth to effective depth of a beam within the recommended range to ensure that the beam is safe and does not fail.