The power rating of a 400-ΩΩ resistor is 0.800 W. Required:
a. What is the maximum voltage that can be applied across this resistor without damaging it?
b. What is the maximum current it can draw?

voltage= 17.88volts

current= 0.04 amps

Explanation:

Step one:

given data

resistance R=400 ohms

Power P= 0.8W

a.  What is the maximum voltage that can be applied across this resistor without damaging it?

the expression relating power and voltage is

P=V^2/R

substituting we have

0.8=V^2/400

V^2=0.8*400

V^2=320

V=√320

V=17.88 volts

the maximum voltage is 17.88volts

b.What is the maximum current it can draw?

we know that from Ohm' law

V=IR

17.88=I*400

I=17.88/400

I=0.04amps

god i hope this !