Disabling NVIDIA card on hybrid graphics laptop

I have MSI GP60 2QE laptop with Intel HD 4600 and NVIDIA 940M graphics. I dual booted Windows 10 with Ubuntu 15.10 and noticed, that on Ubuntu NVIDIA card is always on what makes my battery last about 2h. Can I disable that card and force system to run on Intel integrated graphics? I use Ubuntu only for coding so I don't need advanced graphics enabled. Also, I can't disable card in BIOS since I'm using it on Windows.

Yes, you can:

• Open NVIDIA X Server Settings.
• Go to PRIME Profiles.
• Select Intel.
• Log out and back in or reboot.

Now you are using Intel graphics.

Update addressing your comments that you cannot access NVIDIA X Server Settings:

To open NVIDIA X Server Settings press the Super key (it's the Windows key) and type "NVIDIA".

If it doesn't appear, maybe the installation of the NVIDIA drivers is not complete.
In that case, open a terminal and execute:

sudo apt-get update  
sudo apt-get install nvidia-prime nvidia-settings

Then look for it again and you will find it.