The potential gradient along the length of a uniform wire is \[10\,volt/metre\]. \[B\] and \[C\] are the two points at \[30\,cm\] and \[60\,cm\] point on a meter scale fitted along the wire. The potential difference between \[B\] and \[C\] will be [CPMT 1986]

• A.                    \[3\,volt\]
• B.                                      \[0.4\,volt\]
• C.                    \[7\,volt\]                      
• D.            \[4\,volt\]