A radioactive material has a count rate of 800 per minute it has a half life of 30 seconds how long will it take to decay to a rate of 25 counts per minute

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

How are series and parallel circuits simililar? both have multiple paths for electrons to travel. both require resistors in their circuits. both require a switch to complete the circuit. both have at least one path for electrons to travel.

I’ve been stuck on this for a while