Question

A variable reluctance tachometer has 180 teeth on rotor. The speed of shaft on which mounted in 1800 . The frequency of output pulses is
1. 1800 Hz
2. 3600 Hz
3. 4800 Hz
4. 5400 Hz

Answer 1

Correct Answer - Option 4 : 5400 Hz

Concept:

In variable reluctance tachometer,

Frequency of output pulse = (No. of teeth on the rotor) × (speed of shaft).

Calculation:

Given:

No. of teeth = 180, speed = 1800 rpm

So, the frequency of the output pulse will be:

\(= \frac{{\left( {180 \times 1800} \right)}}{{minute}}\)

\( = \left( {\frac{{180 \times 1800}}{{60}}} \right)/sec\)

= 5400/sec