Answer:
The dimension is L
Explanation:
Dimension analysis is a method of representing quantities majorly with respect to some fundamental quantities of mass (M), length (L), time (T).
A sphere has a definite volume which relates to its radius by:
V = 


In this equation  is a dimensionless quantity, and the unit of v is
 is a dimensionless quantity, and the unit of v is  .
. 
But, metre is a measure of length, thus it has a dimension of L.
So that,
 ≅
 ≅ 
Then,
  =
 = 
Find the cube root of both sides to have,
r = L
Therefore, the dimension of the radius of a sphere is L.
 
        
             
        
        
        
Answer:
1.6 x 10^-5 T
Explanation:
i = 4 A
r = 0.05 m 
The magnetic field due to long wire at a distance r is given by 

B = 10^-7 x 2 x 4 / 0.05
B = 1.6 x 10^-5 T
 
        
             
        
        
        
B IS YOUR ANSWER.
Soft sound has small amplitude and louder sound has large amplitude. Since, the second wave has large amplitude, it will have the loudest sound.
 
        
             
        
        
        
Answer:
Explanation:
Charge on uranium ion = charge of a single electron 
= 1.6 x 10⁻¹⁹ C 
charge on doubly ionised iron atom = charge of 2 electron
= 2 x 1.6 x 10⁻¹⁹ C = 3.2 x 10⁻¹⁹ C 
Let the required distance from uranium ion be d . 
force on electron at distance d from uranium ion
= 9 x 10⁹ x 1.6 x 10⁻¹⁹ / r²
force on electron at distance 61.10 x 10⁻⁹ - r from iron  ion
= 9 x 10⁹ x 3.2 x 10⁻¹⁹ / (61.10 x 10⁻⁹ - r )²
For equilibrium ,
9 x 10⁹ x 1.6 x 10⁻¹⁹ / r² = 9 x 10⁹ x 3.2 x 10⁻¹⁹ / (61.10 x 10⁻⁹ - r )²
2 d² = (61.10 x 10⁻⁹ - r )²
1.414 r = 61.10 x 10⁻⁹ - r 
2.414 r = 61.10 x 10⁻⁹
r = 25.31 nm . 
 
        
             
        
        
        
The answer is (a).
Golf balls have a higher density than water hence sink to the bottom.