Answer:
c. 3/2 mg
Explanation:
Given that the acceleration of an elevator is 1/2 g upward.
The reading on the scale of the elevator is the net external force acting on the elevator.
Let the force F acting on the elevator as shown,
By using Newton's 2nd law, 
where,
is the net force acting on the elevator.
m is the mass of the elevator,
a is the acceleration of the elevator, as given a=1/2 g upward.
So, 

So, the reading on the scale in the elevator is
.
Hence, option (c) is correct.
Answer:
Explanation:
The wires are in circular shape . They have common center .
magnetic field due to circular wire is given by the formula
B = 
where I is current , r is radius of the coil .
magnetic field due to inner wire
= 
magnetic field due to outer wire
= 
These should be equal and opposite so that by cancelling each other , they create zero field.
= 
I = 16.66 A
Direction of current should be in opposite direction ie anticlockwise when looking from above.
As one moves farther and farther from the Sun, the distance between adjacent planets is greater.
Answer:
The lowest energy of electron is the ground state.
Explanation: