Answer:
True
Explanation:
An independent variable is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable. You are changing light or dark
I haven't worked on Part-A, and I don't happen to know the magnitude of the gravitational force that the Sun exerts on the Earth.
But whatever it is, it's exactly, precisely, identical, the same, and equal to the magnitude of the gravitational force that the Earth exerts on the Sun.
I think that's the THIRD choice here, but I'm not sure of that either.
Answer:
True
Explanation:
The image produced a convex mirror is always virtual irrespective of location. The size of the image is always smaller than the object. In a plane mirror the distance of the object and the distance of the image is same. But in a convex the image distance is always less than the object distance.
So, this statement is true.
Answer:
The number of turns in secondary coil is 4000
Explanation:
Given:
Current in primary coil
A
Current in secondary coil
A
Number of turns in primary coil 
In case of transformer the relation between current and number of turns is given by,

For finding number of turns in secondary coil,



Therefore, the number of turns in secondary coil is 4000