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Electrical Energy and Power for JEE: 56 solved questions

Real JEE paper questions on electrical energy and power, part of current electricity. Each opens with the options, the correct answer and a step-by-step solution. Papers run from 2002 to 2026. No sign-in needed to read them.

What this topic asks

• Heating and power in resistors — 33 questions
• Rated bulbs and appliances — 19 questions
• Maximum power transfer — 4 questions

All 56 questions with solutions

• A 6.0 volt battery is connected to two light bulbs as shown in figure. Light bulb 1 has resistance 3 ohm whil… JEE Main Online 2012
• Model a torch battery of length l to be made up of a thin cylindrical bar of radius a and a concentric thin c… JEE Main 3rd Sept 1st Shift 2020
• Two resistors of 200 Ω and 400 Ω are connected in series with a battery of 100 V. A bulb rated at 200 V, 100… JEE Main 2nd April 2nd Shift 2026
• A battery with EMF E and internal resistance r is connected across a resistance R. The power consumption in R… JEE Main 21st Jan 2nd Shift 2026
• An electric power line having total resistance of 2 Ω, delivers 1 kW of power at 250 V. The percentage effici… JEE Main 22nd Jan 2nd Shift 2026
• The battery of a mobile phone is rated as 4.2 V, 5800 mAh. How much energy is stored in it when fully charged? JEE Main 2nd April 1st Shift 2025
• There are n number of identical electric bulbs, each is designed to draw a power p independently from the mai… JEE Main 4th April 2nd Shift 2025
• An electric bulb rated 50 W - 200 V is connected across a 100 V supply. The power dissipation of the bulb is JEE Main 4th April 2nd Shift 2024
• The ratio of heat dissipated per second through the resistance 5 Ω and 10 Ω in the circuit given below is [Fi… JEE Main 5th April 2nd Shift 2024
• The number of electrons flowing per second in the filament of a 110 W bulb operating at 220 V is (Given e=1.6… JEE Main 6th April 2nd Shift 2024
• Water boils in an electric kettle in 20 minutes after being switched on. Using the same main supply, the leng… JEE Main 8th April 2nd Shift 2024
• When a potential difference V is applied across a wire of resistance R, it dissipates energy at a rate W. If… JEE Main 30th Jan 2nd Shift 2024
• By what percentage will the illumination of the lamp decrease if the current drops by 20%? JEE Main 31st Jan 2nd Shift 2024
• Two identical heater filaments are connected first in parallel and then in series. At the same applied voltag… JEE Main 11th April 1st Shift 2023
• Different combination of 3 resistors of equal resistance R are shown in the figures. The increasing order for… JEE Main 13th April 1st Shift 2023
• Ratio of thermal energy released in two resistors R and 3R connected in parallel in an electric circuit is JEE Main 29th Jan 1st Shift 2023
• The H amount of thermal energy developed by a resistor in 10 s when a current of 4 A is passed through it. If… JEE Main 31st Jan 2nd Shift 2023
• Due to cold weather a 1 m water pipe of cross-sectional area 1 cm² is filled with ice at -10°C. Resistive hea… JEE Main 1st Sept 2nd Shift 2021
• An electric appliance supplies 6000 J per min heat to the system. If the system delivers a power of 90 W, how… JEE Main 26th Aug 1st Shift 2021
• In the given figure, the emf of the cell is 2.2 V and if internal resistance is 0.6 Ω. Calculate the power di… JEE Main 26th Aug 1st Shift 2021
• An electric bulb of 500 watt at 100 volt is used in a circuit having a 200 V supply. Calculate the resistance… JEE Main 26th Aug 2nd Shift 2021
• A resistor develops 500 J of thermal energy in 20 s when a current of 1.5 A is passed through it. If the curr… JEE Main 16th March 2nd Shift 2021
• An electrical power line, having a total resistance of 2 Ω, delivers 1 kW at 220 V. The efficiency of the tra… JEE Main 5th Sept 1st Shift 2020
• In a building, there are 15 bulbs of 45 W, 15 bulbs of 100 W, 15 small fans of 10 W and 2 heaters of 1 kW. Th… JEE Main 7th Jan 2nd Shift 2020
• A cell of internal resistance r drives current through an external resistance R. The power delivered by the c… JEE Main 8th April 2nd Shift 2019
• The resistive network shown below is connected to a D.C. source of 16 V. The power consumed by the network is… JEE Main 12th April 1st Shift 2019
• A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power… JEE Main 10th Jan 2nd Shift 2019
• Two equal resistances when connected in series to a battery, consume electric power of 60 W. If these resista… JEE Main 11th Jan 1st Shift 2019
• Two electric bulbs, rated at (25 W, 220 V) and (100 W, 220 V), are connected in series across a 220 V voltage… JEE Main 12th Jan 1st Shift 2019
• A constant voltage is applied between two ends of a metallic wire. If the length is halved and the radius of… JEE Main Online 2018
• The figure shows three circuits I, II and III which are connected to a 3 V battery. If the powers dissipated… JEE Main Online 2017
• In the circuit shown, the resistance r is a variable resistance. If for r=fR, the heat generation in r is max… JEE Main Online 2016
• The resistance of an electrical toaster has a temperature dependence given by R(T)=R₀[1+α(T-T₀)] in its range… JEE Main Online 2016
• In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The v… JEE Main 2014
• Four bulbs B₁, B₂, B₃ and B₄ of 100 W each are connected to 220 V main as shown in the figure. The reading in… JEE Main Online 2014
• The supply voltage to a room is 120 V. The resistance of the lead wires is 6 Ω. A 60 W bulb is already switch… JEE Main 2013
• Which of the four resistances P, Q, R and S generate the greatest amount of heat when a current flows from A… JEE Main Online 2013
• Two electric bulbs marked 25 W-220 V and 100 W-220 V are connected in series to a 440 V supply. Which of the… JEE Main 2012
• An electric bulb is rated 220 volt - 100 watt. The power consumed by it when operated on 110 volt will be JEE Main 2006
• The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of… JEE Main 2005
• A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated wil… JEE Main 2005
• Time taken by a 836 W heater to heat one litre of water from 10°C to 40°C is JEE Main 2004
• A 220 volt, 1000 watt bulb is connected across a 110 volt mains supply. The power consumed will be JEE Main 2003
• A wire when connected to 220 V mains supply has power dissipation P₁. Now the wire is cut into two equal piec… JEE Main 2002
• If in the circuit, power dissipation is 150 W, then R is [Figure: a resistor R and a 2 Ω resistor in parallel… JEE Main 2002
• The heat generated in 1 minute between points A and B in the given circuit, when a battery of 9 V with intern… JEE Main 21st Jan 1st Shift 2026
• A heater is designed to operate with a power of 1000 W in a 100 V line. It is connected in combination with a… JEE Main 8th April 2nd Shift 2024
• In the following circuit, the battery has an emf of 2 V and an internal resistance of 2/3 Ω. The power consum… JEE Main 31st Jan 2nd Shift 2024
• A potential V₀ is applied across a uniform wire of resistance R. The power dissipation is P₁. The wire is the… JEE Main 13th April 1st Shift 2023
• An electrical bulb rated 220 V, 100 W, is connected in series with another bulb rated 220 V, 60 W. If the vol… JEE Main 28th July 2nd Shift 2022
• A resistor develops 300 J of thermal energy in 15 s, when a current of 2 A is passed through it. If the curre… JEE Main 25th June 1st Shift 2022
• Two coils require 20 minutes and 60 minutes respectively to produce same amount of heat energy when connected… JEE Main 29th June 1st Shift 2022
• A uniform heating wire of resistance 36 Ω is connected across a potential difference of 240 V. The wire is th… JEE Main 1st Sept 2nd Shift 2021
• A resistor dissipates 192 J of energy in 1 s when a current of 4 A is passed through it. Now, when the curren… JEE Main 31st Aug 2nd Shift 2021
• An electric bulb rated as 200 W at 100 V is used in a circuit having 200 V supply. The resistance R that must… JEE Main 25th July 1st Shift 2021
• The energy dissipated by a resistor is 10 mJ in 1 s when an electric current of 2 mA flows through it. The re… JEE Main 16th March 2nd Shift 2021