nSims <- 10000
h0 <-numeric(nSims)

for(i in 1:nSims){
x<-rnorm(n = 200, mean = 0, sd = 1)
y<-rnorm(n = 200, mean = 0, sd = 1)
z<-t.test(x,y, var.equal = T)
h0[i]<-z$p.value
}

hist(h0, main="Histogram of p-values [H0 = T, HoV = T, Cell.Eq = T]", xlab=("Observed p-value"), breaks=100)