Answer:
The inductance of solenoid A is twice that of solenoid B
Explanation:
The inductance of a solenoid L is given by
L = μ₀n²Al where n = turns density, A = cross-sectional area of solenoid and l = length of solenoid.
Given that d₁ = 2d₂ and l₂ = 2l₁ and d₁ and d₂ are diameters of solenoids A and B respectively. Also, l₁ and l₂ are lengths of solenoids A and B respectively.
Since we have a cylindrical solenoid, the cross-section is a circle. So, A = πd²/4.
Let L₁ and L₂ be the inductances of solenoids A and B respectively.
So L₁ = μ₀n²A₁l₁ = μ₀n²πd₁²l₁/4
L₂ = μ₀n²A₂l₂ = μ₀n²πd₂²l₂/4
Since d₁ = 2d₂ and l₂ = 2l₁, sub
L₁/L₂ = μ₀n²πd₁²l₁/4 ÷ μ₀n²πd₂²l₂/4 = d₁²/d₂² × l₁/l₂ = (2d₂)²/d₂² × l₁/2l₁ = 4d₂²/d₂² × l₁/2l₁ = 4 × 1/2 = 2
L₁/L₂ = 2
L₁ = 2L₂
So, the inductance of solenoid A is twice that of solenoid B
Frozen water has move volume than water in liquid form
Answer:
B) 35 W
Explanation:
Force applied by child = 75 N = F
Distance travelled by child = 42 m = d
Time traveled for is 1.5 min = 1.5×60 = 90 seconds = t
Work done by the child
W = Fdcosθ
⇒W = 75×42cos0
⇒W = 3150 Joule
Power is defined as work done per unit time

∴ The average power generated by the child is 35 W
Explanation:
Gravitational force
The force of gravity is the force with which the earth, moon, or other massively large object attracts another object towards itself.
Normal force
The normal force is the support force exerted upon an object that is in contact with another stable object.
Friction force
The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it.
Tension force
The tension force is the force that is transmitted through a string, rope, cable or wire when it is pulled tight by forces acting from opposite ends.
Spring force
The spring force is the force exerted by a compressed or stretched spring upon any object that is attached to it.