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:
The answer here is prism. The light passing through prism experiences bending of its multiple wavelength composition which allows it to visibly shows the difference in each of the light's color wavelength, violet bending the most while the least is the color red.
So, option 3 or the ambulance sound waves have more waves and shorter wavelength is the correct reason for ambulance siren having higher pitch compared to fire truck siren
Explanation:
Pitch of any sound wave is determined as the clarity in frequency of notes or the number of times a cycle is repeated for a single second. So pitch is similar to frequency. And frequency is the measure of number of complete cycles in a second. So if the ambulance siren has higher pitch compared to siren of fire truck. Then this means the frequency of ambulance siren is greater than the fire truck siren. As the frequency is more, then from the given options, choice 3 is correct. The ambulance siren have more waves and shorter wavelength. As more the frequency or number of waves, lesser or shorter is the wavelength of sound wave from ambulance.
