Bulbs in series and parallel
This type of question, asked 4 times: 2023, 2024, 2025, 2026. All 6 questions below, oldest first.
Try each one first, then open its answer.
Question 1
2023
36 (b)In an electric circuit three bulbs of 100 W each are connected in series to a source. In another circuit set of three bulbs of the same wattage are connected in parallel to the same source. (i) Will the bulb in the two circuits glow with the same brightness ? Justify your answer. (ii) Now, let one bulb in both the circuits get fused. Will the rest of the bulbs continue to glow in each circuit ? Give reason for your answer.Question 2
2023
16Two LED bulbs of 10W and 5W are connected in series. If the current flowing through 5W bulb is 0.005A, the current flowing through 10W bulb is :Tap an option to check your answer.
Question 3
2023
13Two LED bulbs of 12W and 6W are connected in series. If the current through 12W bulb is 0.06A the current through 6W bulb will be :Tap an option to check your answer.
Question 4
2024
34 (A)(i) State whether the currents and potential difference in all the bulbs will be same or different when in a circuit three bulbs of : (a) same wattage are connected in series. (b) same wattage are connected in parallel. (c) different wattage are connected in series. (d) different wattage are connected in parallel. (ii) Two identical resistors of each are connected to a battery of 6 V. Calculate the ratio of the power consumed by the resulting combinations with (a) minimum resistance and (b) maximum resistance.Question 5
2025
14The minimum number of identical bulbs of rating 4V; 6W, that can work safely with desired brightness, when connected in series with a 240 V mains supply is :Tap an option to check your answer.
Question 6
2026
39 (b)(i) How many bulbs of resistance each should be connected in parallel combination to draw a current of 2 A from a battery of 4 V ? (ii) Name the device used for measuring electric current. How is it connected in a circuit ? (iii) State Joule’s law of heating.