transformer makes use of mutual induction for its operation in which change in magnetic field in one coil due to variation of current , induces voltage in the other coil. so changing magnetic field in the primary coil is very much needed for the transformer. Alternating current is a current which varies with time , hence it is suitable to produce changing magnetic field in the primary coil. on the other hand , the direct current remains constant all the time. hence can not produce a changing magnetic field. so DC current is not useful for transformers.
Answer: 
Explanation:
IMA stands for Ideal Mechanical advantage.
The IMA of pulley system can be defined as the ratio of output force to input force.
From the given pulley system,
The input force = 
The output force = 
Hence, IMA of the given pulley system,
Evidence for the particle nature of light are not: 1. refraction, 2. many colors of light, 3. diffraction. These are all phenomenon that support wave theory of light. Evidence for particle nature of light is photoelectric effect. Because it was discovered that you need discrete energies of light to eject electrons from a metal surface and not continuous as the wave theory of light suggests.
Given speed and the distance that must be covered, the time it will take the ultraviolet light to reach the earth is 3.7 × 10⁴ hours.
<h3>
What is Speed?</h3>
Speed is simply referred to as distance traveled per unit time.
Mathematically, Speed = Distance ÷ time.
Given the data in the question;
- Speed of the Ultraviolet light c = 3.0 × 10⁸m/s = 1.08 × 10⁹km/h
- Distance it must cover d = 4.0 × 10¹³km
We substitute our given values into the expression above.
Speed = Distance ÷ time
1.08 × 10⁹km/h = 4.0 × 10¹³km ÷ t
t = 4.0 × 10¹³km ÷ 1.08 × 10⁹km/h
t = 3.7 × 10⁴ hrs
Therefore, given speed and the distance that must be covered, the time it will take the ultraviolet light to reach the earth is 3.7 × 10⁴ hours.
Learn more about speed here: brainly.com/question/7359669
#SPJ4
Answer:
0.7549kg
Explanation:
The mass of the slice + mass of the remaining cake = total mass of cake.
mass of remaining cake = total mass of cake - the mass of the slice
total mass=0.870kg
mass of slice = 0.1151kg
mass of remaining cake = 0.870 - 0.1151
mass of remaining cake=0.7549kg
