The device is made by the Taiwanese company Asus rather than the firm’s own Motorola hardware unit. It runs the new Jelly Bean version of Android.
An 8GB version will be sold for $199 (£127) from mid-July pitching it directly against Amazon’s Kindle Fire.
The firm also showed off its internet-connected augmented reality glasses revealing the first models would ship in 2013.
The announcements were made at Google’s I/O developers’ conference in San Francisco.
The 7-inch (17.8cm) Nexus tablet features a quad-core CPU (central processing unit) and a 12-core GPU (graphics processing unit).
Having so many cores means the machine can ramp up its processing power when dealing with complicated graphics or running several programs at once, but can use less at other times to extend battery life.
It is a similar size to Amazon’s tablet and Samsung’s Galaxy Tab 2 7.0.
But it has a significantly smaller screen than Apple’s bestselling 9.7-inch (24.6cm) iPad. At 340g (12oz) it is also lighter to hold.
The machine features Google’s Chrome browser as its default option – the first Android device to do so.
The first countries to get the product are the US, UK, Canada and Australia.
The Google Play site said the 8GB model would sell for £159 in the UK, and the 16GB version for £199.
The news follows Microsoft’s announcement last week that it plans to sell its own family of tablets called Surface which will run Windows 8.
Tudor Aw, technology sector head at KPMG Europe said it marked a shift towards Apple’s business model which recognised the advantage of being involved in both hardware and software.
“Following hard on the heels of a similar announcement by Microsoft last week [this] demonstrates that gaining a strong marketshare of the tablet market will be critical to tech players if they want to maintain a strong relationship with their end customers – both consumers and business users,” he said.
“Tech players recognise that given the increasing importance of tablet devices, they can no longer risk selling their software and services solely through other people’s products.”
But one analyst, from Forrester Research, said the Nexus 7’s success was not guaranteed.
“Google’s real tablet problem is the lack of compelling tablet-optimised apps and Google has yet to address how to motivate developers to fill the gap,” said Frank Gillett.
“I also expect Amazon will update the Kindle Fire before October at the latest, and that will have more compelling content thanks to the retailer’s Prime subscription package which includes movies, books and other content.
“I was surprised Google didn’t offer a similar deal to monetise its hardware.”
Google’s co-founder Sergey Brin also took to the stage to showcase the firm’s Glass project – augmented reality glasses that are still in development.
Rather than introduce a demo he brought up live feeds from devices being worn by Google employees sat in a floating airship above San Francisco.
Attendees then watched live footage screened through the headsets as the workers skydived to the roof of a building below.
Cyclists on the same roof then streamed pictures as they jumped over ramps before riding to the main floor of the I/O event.
Next engineers explained the “philosophy” of the equipment, saying that they had placed a screen above the right eye to make it easy to continue interacting with the real world, and a touchpad on one of the sidebars to control it.
They said they envisaged two main uses for the device.
The first, to capture videos and photos taken from the user’s point of view as they took part in activities they wished to record.
The second, to overlay information onto what they are seeing in front of them such as how fast they are moving or the best way to get to another location.
Mr Brin added that the “Glass explorer edition” was being made available for pre-order to US-based developers attending the conference. He said it would cost $1,500 and was set to ship early next year.
While the Nexus tablet had been widely rumoured and Project Glass announced before, the unveiling of another product – the Nexus Q – proved a surprise.
The spherical device is a small Android-powered computer without its own screen. Rather than be used as a standalone unit it is meant to be plugged into a stereo and television system.
It can stream music and videos from other devices allowing both its owner and others to play media files. It can communicate via NFC (near field communication) technology as well as wi-fi and bluetooth.
The firm described the US-manufactured item as the “world’s first ever social streaming device”.
However, other wi-fi media streamers such as the Apple TV, Roku 2 XS and Western Digital’s WD TV Live are sold for less than half the price.