NTA Abhyas JEE Main2020PhysicsUnits and DimensionsPractice
If p represents radiation pressure, C represents the speed of light and q represents radiation energy striking a unit area per second, then non-zero integers a , b and c are such that p a q b C c is dimensionless, then
Options
- Aa = 1 , b = 1 , c = - 1
- Ba = 1 , b = - 1 , c = 1
- Ca = - 1 , b = 1 , c = 1
- Da = 1 , b = 1 , c = 1
Correct answer
B. a = 1 , b = - 1 , c = 1
Step-by-step solution
Here, M 0 L 0 T 0 = M L - 1 T - 2 a M T - 3 b L T - 1 c Or M 0 L 0 T 0 = [ M a + b L - a + c T - 2 a - 3 b - c ] Comparing powers of M , L and T , we get a + b = 0 , - a + c = 0 , - 2 a - 3 b = 0 Solving a = 1 , b = - 1 , c = 1