The following two statements are made with reference to a simply supported under - reinforced $$RCC$$ beam:

$${\rm I}.\,\,\,\,\,\,\,\,\,\,\,\,$$ Failure takes place by crushing of concrete before the steel has yielded.
$${\rm II}.\,\,\,\,\,\,\,\,\,\,$$ The neutral axis moves up as the load is increased.

With reference to the above statements, which of the following applies?

Assume straight line instead of parabola for stress-strain curve of concrete as given below and partial factor of safety as $$1.0.$$

A rectangular under-reinforced concrete section of $$300$$ $$mm$$ width and $$500$$ $$mm$$ effective depth is reinforced with $$3$$ bars of grade $$Fe$$-$$415,$$ each of $$16$$ $$mm$$ diameter. Concrete mix is $$M20.$$

The depth of the neutral axis obtained as per $$IS:$$ $$456$$-$$2000$$ differs from the depth of neutral axis obtained in $$Q.08$$ by

Assume straight line instead of parabola for stress-strain curve of concrete as given below and partial factor of safety as $$1.0.$$

A rectangular under-reinforced concrete section of $$300$$ $$mm$$ width and $$500$$ $$mm$$ effective depth is reinforced with $$3$$ bars of grade $$Fe$$-$$415,$$ each of $$16$$ $$mm$$ diameter. Concrete mix is $$M20.$$

The depth of the neutral axis from the compression fibre is

A continuous beam $$250\,mm \times 450\,mm$$ carries $$6$$ numbers of $$12$$ $$mm$$ diameter longitudinal bars as shown. The factored shear force at the point of inflection is $$200$$ $$kN.$$ Check if the beam is safe in bond. Assume $$M15$$ mix with $${\sigma _{ck}} = 15\,\,N/m{m^2}$$ and mild steel with $${\sigma _y} = 250\,N/m{m^2}.$$ A clear cover of $$25$$ $$mm$$ can be assumed. The design bond stress for mild steel bars in $$M15$$ concrete is specified to be $$1.0\,N/m{m^2}.$$