In order to test my SQL Server Resource Governor setup I needed a query that generates 100 CPU% load. This query will do the trick.
Note: U will need admin privileges for this script.

SELECT MyInt = CONVERT(BIGINT, o1.object_id) + CONVERT(BIGINT, o2.object_id) + CONVERT(BIGINT, o3.object_id)
INTO #temp
FROM sys.objects o1
JOIN sys.objects o2 ON o1.object_id < o2.object_id
JOIN sys.objects o3 ON o1.object_id < o3.object_id

SELECT SUM(CONVERT(BIGINT, o1.MyInt) + CONVERT(BIGINT, o2.MyInt))
FROM #temp o1
JOIN #temp o2 ON o1.MyInt < o2.MyInt

You can check how SQL Server loads the CPU of your server using the following T-SQL script:

DECLARE @CPU_BUSY int, @IDLE int
SELECT @CPU_BUSY = @@CPU_BUSY, @IDLE = @@IDLE 
WAITFOR DELAY '00:00:00:500'
SELECT(@@CPU_BUSY - @CPU_BUSY) / ((@@IDLE - @IDLE + @@CPU_BUSY - @CPU_BUSY) * 1.00) * 100 AS CPUBUSY