Answer:
C. 0.25J
Explanation:
Energy stored in the magnetic field of the inductor is expressed as E = 1/2LI² where;
L is the inductance
I is the current flowing in the inductor
Given parameters
L = 20mH = 20×10^-3H
I = 5A
Required
Energy stored in the magnetic field.
E = 1/2 × 20×10^-3 × 5²
E = 1/2 × 20×10^-3 × 25
E = 10×10^-3 × 25
E = 0.01 × 25
E = 0.25Joules.
Hence the energy stored in the magnetic field of this inductor is 0.25Joules
At the center, when the bob is hanging straight down
Depending on which type of motor you're talking about, but the first 3 are true. A stronger magnetic field in a DC motor will slow it down but increase its torque.
The amount of current in the motor will control the magnetic fields and therefore affect the speed (and torque). In an induction motor, the rotational speed is given by

where f is the line frequency and p is the number of poles. Thus fewer poles makes it go faster.
Speed. This ONLY includes the miles per hour. If it had a direction it would be velocity.
Answer:
D) not swim in or drink the water from the stream
Explanation:
Low pH means the water is acidic which is harmful to your skin as it can cause burns and irritations. So any means of contacting with water is not healthy. The damage to the skin happens as in acidic water it has more H+ than in the neutral water and the extra H+ ions can ionize the atoms which are combined to form different compounds in the skin when in contact.