Statistical Inference — size and bias of a uniform critical region

Consider the distribution having probability density function of a random variable X as $f(x,\theta)=\frac{1}{\theta}$, $0\le x\le\theta$; $0$ elsewhere. Let $1\le X\le 1.5$ be the critical region to test the hypothesis $H_0:\theta=1.5$ against $H_1:\theta=2$. Then