Answer with Explanation:
We are given that
Resistance of solenoid,R=4.3 ohm
Magnetic field,B=
Current,I=4.6 A
Diameter of wire,d=0.5 mm=
Radius of wire,r=

Radius of solenoid,r'=1 cm=

Resistivity of copper,
We know that

Where 
Using the formula


Number of turns of wire=
Number of turns of wire=
Hence, the number of turns of the solenoid,N=799
Magnetic field in solenoid,B=






Length of solenoid=12.5 cm
1m=100 cm
Answer:
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It depends on what type of solid
Answer:
No, some energy will be dissipated energy due to work of air resistance.
a. Speed is defined as rate of change of distance per unit time whereas velocity is defined as rate of change of displacement per unit time.
b.
is the total time taken in the trip
c.
is the total distance
d.
towards right from the starting point.
e. 
f.
towards right.
Explanation:
a.
Speed is a scalar quantity while velocity is a vector quantity.
Speed is defined as rate of change of distance per unit time whereas velocity is defined as rate of change of displacement per unit time.
Speed is a directionless quantity while velocity constitutes direction.
b.
<em>Total time of round trip when we're given:</em>
- distance travelled to the right,

- speed while travelling to the right,

- time spent at gas station,

- time spent while travelling back towards the left,

- speed while travelling to the left,

<em>Now time taken for travelling towards right:</em>



<u>Therefore total time taken in the round trip:</u>



c.
<em>Now, distance travelled towards left:</em>



<u>Therefore total distance:</u>



d.
Now, total displacement:


towards right from the starting point.
e.
<u>Average speed:</u>



f.
<u>Average velocity:</u>


towards right.