The potential difference across a resistor increases by a factor of 2. how does the current change? (ohm's law: v = ir) a. it decreases by a factor of 2. b. it increases by a factor of 4. c. it increases by a factor of 2. d. it decreases by a factor of 4.

The two required components for a generator

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z

Awheel of mass 48 kg is lifted to a height of 0.8 m. how much gravitational potential energy is added to the wheel? acceleration due to gravity is g = 9.8 m/s2. a. 30.4 j b. 3.1 j c. 297.9 j d. 11,321 j