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Saturday, 31 October

JEE Main 2021 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 24 February 2021, Shift 2, Physics Q25

Question 25 of 90 in this shift, Physics question 25 of 30, Section B.

Two cars are approaching each other at an equal speed of 7.2 km/hr. When they see each other, both blow horns having frequency of 676 Hz. The beat frequency heard by each driver will be __________ Hz. [Velocity of sound in air is 340 m/s.]

Official answer

8

NTA final key.

Chapter
Waves
Topic
Doppler Effect
Idea tested
Doppler Beat Frequency Calculation

Same idea in other shifts

Asked 2× in all
  1. 25 Jul 2022, Shift 1 · Q55An observer is riding on a bicycle and moving towards a hill at 18 km h−118\ \mathrm{km\,h^{-1}}. He hears a sound from a source at some distance…MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.