1)Two metal spheres are suspended from insulation threads. A negatively charged rod is brought near these spheres. One shere is pushed away from the rod and the other atracted towards it. Describe the behavior of the spheres.

I know one has to be negative and the other positive but I don't know what else they're looking for.

2)The electricity received at an electric substation has a potential difference of 2.80 x 10^5 V. If the required output is 440 V, what should be the ratio of the turns of the step-down transformer?

I know the transformer equation is:

Is/Ip = Vp/Vs = Np/Ns

Thats the closest thing I could find regarding this problem

2. Use that equation to get the turns ratio Np/Ns

1. The sphere repulsed is negative. The attracted sphere could be neutral, or positive. If neutral, what is happening is that electrons on the surface are repulsed, and move to the opposite side, leaving a net positive side on the near side. Since the net positive side is closest, it has more force of attraction than the negative side further away, so it is attracted.

so it would be:

Vp/Vs = Np/Ns
(2.80 x 10^5)/(440)

I'm not sure on the values

1) Based on the behavior described, it appears that the negatively charged rod has induced a separation of charges in the metal spheres. When a negatively charged rod is brought close to the spheres, it repels the negatively charged electrons in one sphere, causing an accumulation of positive charge in that sphere. This positive charge is attracted to the negatively charged rod, causing the sphere to be pushed away from it. On the other hand, the electrons in the other sphere are attracted to the positively charged rod, causing an accumulation of negative charge. This negative charge is attracted to the rod, resulting in the sphere being attracted towards it.

In summary, one sphere becomes positively charged and is pushed away from the negatively charged rod, while the other sphere becomes negatively charged and is attracted towards the rod.

2) To solve this problem, you can use the transformer equation you mentioned:

Is/Ip = Vp/Vs = Np/Ns

Where:
Is = secondary current
Ip = primary current
Vp = primary voltage
Vs = secondary voltage
Np = number of turns in the primary coil
Ns = number of turns in the secondary coil

Since the problem asks for the ratio of turns in the step-down transformer, we can rewrite the equation as:

Ns/Np = Vs/Vp

In this case, the primary voltage (Vp) is given as 2.80 x 10^5 V and the required output voltage (Vs) is given as 440 V. We can substitute these values into the equation:

Ns/Np = 440 V / 2.80 x 10^5 V

Simplifying this expression, we obtain the ratio of turns in the step-down transformer:

Ns/Np = 1.57 x 10^-3

Therefore, the ratio of turns should be approximately 1.57 x 10^-3.