sql server 2012 t-sql

Create Table Student_Grades
(
StudentID Int
,FirstName Varchar(100)
,Course Varchar(100)
,Score Int
)

-- Insert Rows in a Table Student_Grades
Insert Student_Grades

Select 1,'Rama','DSP',100
Union
Select 2,'Arun','DSP',80
Union
Select 3,'Sai','DSP',90
Union
Select 4,'Priya','DSP',70
Union
Select 5,'Shashi','AppliedPhysics',10
Union
Select 6,'Karthik','AppliedPhysics',45
Union
Select 7,'Ashok','AppliedPhysics',60
Union
Select 5,'Shashi','Java',20
Union
Select 5,'Shashi','Maths',30
Union
Select 1,'Rama','Maths',75
Union

Select 2,'Arun','Maths',65

this is my table

My query is 

WAQ TO DISPLAY TOPPER IN EACH COURSE

i have tried but i m unable to get the results...

any help is highly appreciated and thanks in advance..