Answer:
The winding density of the solenoid, n = 104 turns/m
Explanation:
Given that,
Length of the solenoid, l = 0.7 m
Radius of the circular cross section, r = 5 cm = 0.05 m
Energy stored in the solenoid, 
Current, I = 0.4 A
To find,
The winding density of the solenoid.
Solution,
The expression for the energy stored in the solenoid is given by :

Where
L is the self inductance of the solenoid

n is the winding density of the solenoid


n = 104 turns/m
So, the winding density of the solenoid is 104 turns/m
Answer:
Option B and C are True
Note: The attachment below shows the force diagram
Explanation:
The weight of the two blocks acts downwards.
Let the weight of the two blocks be W. Solving for T₁ and T₂;
w = T₁/cos 60° -----(1)
w = T₂/cos 30° ----(2)
equating (1) and (2)
T₁/cos 60° = T₂/cos 30°
T₁ cos 30° = T₂ cos 60°
T₂/T₁ = cos 30°/cos 60°
T₂/T₁ =1.73
Therefore, option a is false since T₂ > T₁
Option B is true since T₁ cos 30° = T₂ cos 60°
Option C is true because the T₃ is due to the weight of the two blocks while T₄ is only due to one block.
Option D is wrong because T₁ + T₂ > T₃ by simple summation of the two forces, except by vector addition.
Explanation:
Formula to calculate electric field because of the plate is as follows.
E =
=
=
Now, we will consider that equilibrium of forces are present there. So,
ma = qE
a =
=
According to the third equation of motion,
or, d = 
= 
= 0.254 m
Thus, we can conclude that
the proton will travel 0.254 m before reaching its turning point.
Given :
Thin hoop with a mass of 5.0 kg rotates about a perpendicular axis through its center.
A force F is exerted tangentially to the hoop. If the hoop’s radius is 2.0 m and it is rotating with an angular acceleration of 2.5 rad/s².
To Find :
The magnitude of F.
Solution :
Torque on hoop is given by :
( Moment of Inertia of hoop is MR² )
Putting value of M, R and α in above equation, we get :

Therefore, the magnitude of force F is 25 N.
Hence, this is the required solution.
Transverse waves travel on a direction that is perpendicular to the motion of the particles (or whatever medium is waving) So the particles must be moving east to west, which is transverse to the north-south motion of the wave