Learn

Saturday, 31 October

JEE Main 2022 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 25 July 2022, Shift 1, Physics Q55

Question 55 of 90 in this shift, Physics question 25 of 30, Section B.

An 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 behind him directly as well as after its reflection from the hill. If the original frequency of the sound as emitted by source is 640640 Hz and velocity of the sound in air is 320320 m/s, the beat frequency between the two sounds heard by observer will be ______ Hz.

Official answer

20

NTA final key (2022 Session 2).

Chapter
Waves
Topic
Doppler Effect
Idea tested
Doppler Beat Frequency Calculation

Same idea in other shifts

Asked 2× in all
  1. 24 Feb 2021, Shift 2 · Q25Two 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.…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.