pinyin: zhuān,

Chinese phrase: 专心 zhuān xīn - (sb) be concentrated, be absorbed
专家 zhuān jiā - expert

Examples:
砖
pinyin: zhuān, brick

传
pinyin: zhuàn
Chinese phrase: 传记 zhuàn jì - biography, a written record of a person's life

转
pinyin: zhuǎn & zhuàn
Chinese phrase: 转身 zhuǎn shēn - (of a person) turn around
旋转 xuán zhuàn - to rotate, revolve