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.
