Factorise m2+7m−60−16n2
(m+3+4n)(m+3−4n)
(m+3−4n)(m+3−4n)
(m−3+4n)(m−3−4n)
(m+2+4n)(m+2−4n)
Given that m2+6m+9−16n2
m2+6m+9=(m+3)2
16n2=(4n)2
Hence using difference of squaresx2−y2=(x+y)(x−y)
Hence x=(m+3) and y=4n
= (m+3+4n)(m+3−4n)
Two equal and opposite charges of 4×10−8C when placed 2×10−2cm away, form a dipole. If this dipole is placed in an external electric field of 4×108 newton/coulomb, the value of maximum torque and the work done in rotating it through 180o will be
The wavelength range of white light is :
(a) 4000 nm to 8000 nm
(b) 40 nm to 80 nm
(c) 400 nm to 800 nm
(d) 4 nm to 8 nm.