Complete Question
How many turns are in its secondary coil, if its input voltage is 120 V and the primary coil has 210 turns.
The output from the secondary coil is 12 V
Answer:
The value is 
Explanation:
From the equation we are told that
The input voltage is 
The number of turns of the primary coil is 
The output from the secondary is 
From the transformer equation

Here
is the number of turns in the secondary coil
=> 
=>
=>
Answer:
I) 420000J
ii)
Explanation:
(I) so you can use the formula for quantity of heat then substitute the values given
formula-Q=mc∆9
Answer:
A.
Explanation:
I think it might be the big number A
Answer:
K.Eₓ = 4 K.E
K.Eₓ = 9 K.E
Explanation:
Th formula for the kinetic energy of a body is given as follows:
---------------equation (1)
where,
K.E = Kinetic Energy of Automobile
m = mass of automobile
v = speed of automobile
For twice speed:
vₓ = 2v
then,

using equation (1):
<u>K.Eₓ = 4 K.E</u>
For thrice speed:
vₓ = 3v
then,

using equation (1):
<u>K.Eₓ = 9 K.E</u>
Na is in the first column on the periodic table so therefore it would have 1 valence electron
D 1