If you will cast your desktop from your Chrome OS or Mac computers, you will see contents on your TV but you will not be able to hear the audio from computer. You can cast your desktop or laptop content on your TV by following these steps or you can also Download Chromecast App
From Chrome Settings Menu:
- Navigate to the settings menu of Chrome at the upper right corner of browser in Chrome toolbar. Now tap the cast button.
- Next it will ask you where you want to cast in the option cast to and small drop down will appear. Click on that menu to change the source.
- Click on the option of Cast Desktop.
- Choose the Chromecast device that you want to cast to.