When a wire is moved inside uniform magnetic field then its free electrons will experience magnetic force on it due to which wire will have potential difference at its ends.
Now here we will have magnetic field due to earth and wire is moving in this constant field so induced emf is given by formula

given that



now by using the above formula we will have



Answer:
Explanation:
As the circuit is parallel, then there is no effect of other branches as the potential difference across each arm is same.
It depends on the circuit. Sometimes it becomes a bit weaker, sometimes it stays the same.
Answer:
The new force becomes 4 times the initial force.
Explanation:
The force of attraction or repulsion is given by the relation as follows :

Where
d is the distance between the interacting charges
F is inversely proportional to the distance between charges.
If the distance is halved, d'=(d/2), new force is given by :

So, the new force becomes 4 times the initial force.
Answer:
The inverse of f equals the inverse of d Subscript o Baseline plus the inverse of d Subscript I Baseline.
Explanation:
The lens equation shows the relation among focal length of the lens, image distance and object distance. It can be expressed as:
=
+ 
where: f is the focal length of the lens,
is the object distance to the lens and
is the image distance to the lens.
The lens equation can be used to determine the unknown value among the variables f ,
and
.