Answer:
A. Step-up voltage transformers have fewer turns in the primary than in the secondary winding.
Explanation:
A step-up transformer is a transformer that transform a lower voltage in input into a higher voltage in output.
The transformer equation states that:
where
Vp is the voltage in the primary winding
Vs is the voltage in the secondary winding
Np is the number of turns in the primary winding
Ns is the number of turns in the secondary winding
we can re-arrange the equation as
For a step-up voltage,
so
which implies also
so, the primary winding has fewer turns than the secondary coil.
Answer:
Explanation:
power rating of the coffee pot,
volume of water to be boiled,
initial temperature of water,
mass of aluminium in the pot,
specific heat of aluminium,
specific heat of water,
<em>Considering that the water and aluminium are always at the same temperature.</em>
<u>Now the heat required to bring the water in the pot to 100°C:</u>
Therefore time required to boil the water:
Answer:
w = 0.189 rad/ s
Explanation:
This exercise we work with the conservation of the moment, the system is made up of the merry-go-round and the child, for which we write the moment of two instants
Initial
L₀ = I₀ w₀
Final
= I w
L₀ = L_{f}
I₀ w₀ = I_{f} w
.w = I₀/I_{f} w₀
The initial moment of inertia is
I₀ = 500 kg. m2
The final moment of inertia
= 500 + m r²
I_{f} = 500 + 20 1.5
I_{f} = 530 kg m²
Initial angular velocity
w₀ = 0.20 rad / s
Let's calculate
w = 500/530 0.20
w = 0.189 rad / s
The answer is A, an insulator.
Answer:
Explanation:
a ) speed of passenger = circumference / time
= 2π R / Time
= 2 x 3.14 x 50 / 60
= 5.23 m /s
b )
centrifugal force = m v² /R
= (882 /9.8 ) x 5.23² / 50
= 77.47 N
Apparent weight at the highest point
real weight - centrifugal force
= 882 - 77.47
= 804.53 N
Apparent weight at the lowest point
real weight + centrifugal force
= 882 +77.47
= 959.47 N
c ) if the passenger’s apparent weight at the highest point were zero
centrifugal force = weight
mv² /R = mg
v² = gR
= 9.8 X 50
v = 22.13 m /s
d )
apparent weight
mg - mv² / R
= 882 - (882 / 9.8 )x 22.13²/50
= 882 + 882
= 1764 N
=