While out for a walk with his mother, lance notices a large, cylindrical gray box high atop a telephone pole. his mother explains that it is a transformer. this transformer takes 6000v from the power company and steps it down to the 240 v supplied to each of the houses on the street, with the use of a secondary coil containing 100 turns. how many turns are there in the primary coil?

The primary coil of the transformer has 2500 turns.

Explanation:

A step-down transformer is an electrical device which is used to decrease the voltage of electricity.

It consists of two coils with different number of turns.

number of turns on a coil is directly proportional to voltage.

The ratio of Number of turns = Ratio of voltage changed

Let Np = number of turns in primary coil = ?

Ns = number of turns in secondary coil = 100

Vi = Voltage taken by Transformer = 6000

Vf = Voltage after transformation = 240 V

Now, we know that:

Np/Ns = Vi/Vf

⇒ Np = (Vi/Vf)*Ns

Np = (6000/240)*100

Np = 2500 turns

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.