An electricity company wants to reduce wasted energy across a town. For the same amount of money, they can either: Use 20% of the wasted
energy from the power station to heat their offices. Install new power
lines which only waste half the energy of the old ones. Replace all the
bulbs in the town with LED bulbs, which are 99% efficient. Explain which of
these things they should do.

Which statement correctly describes the current in a circuit that is made up of any two resistors connected in parallel with a battery? a. the current in the battery and in each resistor is the same b. the current the battery equals to the sum of the currents in the resistors c. the current in the battery is less than the current in either resistor d. the current in the battery equals to the product of the currents in the resistors

A20 cm long spring is attached to a wall. the spring stretches to a length of 22 cm when you pull on it with a force of 100 n. what is the spring constant

The field between two charged parallel plates is kept constant. if the two plates are brought closer together, the potential difference between the two plates either a) decrease b) does not change c) increase?