1. 
Explanation:
We have:
voltage in the primary coil
voltage in the secondary coil
The efficiency of the transformer is 100%: this means that the power in the primary coil and in the secondary coil are equal

where I1 and I2 are the currents in the two coils. Re-arranging the equation, we find

which means that the current in the secondary coil is 14% of the value of the current in the primary coil.
2. 5.7 V
We can solve the problem by using the transformer equation:

where:
Np = 400 is the number of turns in the primary coil
Ns = 19 is the number of turns in the secondary coil
Vp = 120 V is the voltage in the primary coil
Vs = ? is the voltage in the secondary coil
Re-arranging the formula and substituting the numbers, we find:

Answer:
b. 0.6m/s, 0.7m/s, 0.61m/s, 0.62m/s
Explanation:
Precision of a measurement is the closeness of the experimental values to one another. Hence, experimental measurements are said to be precise if they are close to each other irrespective of how close they are to the accepted value. Precision can be determined by finding the range of each experimental value. The measurement with the LOWEST RANGE represents the MOST PRECISE.
Note: Range is the highest value - lowest value
Set A: 1.5 - 0.8 = 0.7
Set B: 0.7 - 0.6 = 0.1
Set C: 2.4 - 2.0 = 0.4
Set D: 3.1 - 2.9 = 0.2
Set B has the lowest range (0.1), hence, represent the most precise value.
Answer:
8672
Explanation:
multiply the length value by 100
Answer:
The smallest separation distance between the speakers is 0.71 m.
Explanation:
Given that,
Two speakers, one directly behind the other, are each generating a 240-Hz sound wave, f = 240 Hz
Let the speed of sound is 343 m/s in air. The speed of sound is given by the formula as :

To produce destructive interference at a listener standing in front of them,

So, the smallest separation distance between the speakers is 0.71 m. Hence, this is the required solution.
The re<span>sistance of the second wire is 16 R.
where R is the resistance of the first wire.
R = </span>ρ

where l = length of the wire
A = area of the wire
A =

where, r =

Thus, on finding the ratio of resistance of the two wires, we get,

here, R1 = R
l1 = 8m
l2 = 2m
A1=π

A1=π

we get. R2 = 16R