i really need !
(science) (15 pts)

1. my amplifier uses a filament that requires a maximum of 5 volts at a current of 15 amperes.
calculate the resistance of the tube. (round to no more than two numbers to the right of the decimal)

2. how many ohms of resistance are present in a light bulb that draws 2 amperes at 120 volts?

3. a 250 watt radio will draw how many amps when operating on 240 volts? (round to no more than two numbers to the right of the decimal)

The problems of physics that are given here can be solved using Ohms laws. As per the Ohms law, we can write
Resistance = Current/Voltage.
Now coming to the questions that are given.
1. In this question,
Current = 15 amperes
Voltage = 5 volts
Then
Resistance = 5/15
                   = 1/3
                   = 0.33 ohms
So the resistance of the tube will be 0.33 ohms
2. Given information's are noted below
Current = 2 amperes
Voltage = 120 volts
Resistance = 120/2
                   = 60 ohms
 So 60 ohms of resistance is present in the bulb.
3. Given information's
Current = 250 watt
Voltage = 240 volts
Resistance = 250/240
                   = 25/24
                   = 1.04 ohms.
The radio will draw 1.04 ohms.