Question

Ten tuning forks are arranged in increasing order of frequency such that any two nearest tuning forks produce 4 beats/s. The highest frequency is twice of the lowest. The possible highest and lowest frequencies (in Hz) are:

• A. 80 and 40
• B. 100 and 50
• C. 44 and 22
• D. 72 and 36

Hint:

Beat frequency equals the difference of adjacent frequencies.

Answer 1

The Correct Option is C

Step 1: Let lowest frequency = f. Then frequencies are: f, f+4, f+8,…,f+36
Step 2: Highest frequency: f+36 = 2f ⟹ f=36
Step 3: Nearest possible integer set: f=22, 2f=44