Agroup of two or more stars is called a a. solar system b. neutron star c. protostar d. star system

Me plz i don’t know the charges on each of these

The step-down transformer gives a current of 10a at 24v if the primary voltage is 240v calculate the 1_primary current 2_the power input 3_the power output

The diagram shows a wave. the quantity shown is the amplitude. this quantity is directly proportional to which of these other quantities? a) energy b) frequency c) period d) wavelength