Most Important Selected Qs for JEE AdvancedPhysicsUnits and Dimensions
The dimension of stopping potential V 0 in photoelectric effect in units of Planck’s constant ‘ h ’, speed of light ‘ c ’ and Gravitational constant ‘ G ’ and ampere A is:
Options
- Ah 1 3 G 2 3 c 1 3 A - 1
- Bh 0 c 5 G - 1 A - 1
- Ch - 2 3 c - 1 3 G 4 3 A - 1
- Dh 2 G 3 2 c 1 3 A - 1
Correct answer
B. h 0 c 5 G - 1 A - 1
Step-by-step solution
V = K ( h ) a ( I ) b ( G ) c ( C ) d (V is voltage) We know [ h ] = M L 2 T - 1 [ I ] = A [ G ] = M - 1 L 3 T - 2 [ C ] = L T - 1 [ V ] = M L 2 T - 3 A - 1 M L 2 T - 3 A - 1 = ( M L 2 T - 1 ) a ( A ) b ( M - 1 L 3 T - 2 ) c ( L T - 1 ) d M L 2 T - 3 A - 1 = M a - c L 2 a + 3 c + d T - a - 2 c - d A b a - c = 1   . . . . . ( 1 ) 2 a + 3 c + d = 2   . . . . . ( 2 ) - a - 2 c - d = - 3   . . . . . ( 3 ) b = - 1     . . . ( 4 ) On solving c = - 1 a = 0 d = 5 ,   b = - 1 V = K ( h )