The answer you are looking for is B, hope this helps.
Answer:
The correct answer is "4.26 m".
Explanation:
Given:
Wavelength,

or,

Distance,

or,

Distance between the 1st and 2nd dark fringes,
As we know,
⇒ 
or,
⇒ 
By substituting the values, we get




Answer: True.
Explanation:
A resistance force is also known as friction. And the efficiency of a machine is affected by friction.
A machine of lower efficiency has higher magnitude of friction than a machine of higher efficiency.
Therefore, To obtain the same resistance force, a greater force must be exerted in a machine of lower efficiency than in a machine of higher efficiency. This is true