Question

The coefficient of discharge for an external mouthpiece depends upon
1. Velocity of liquid
2. Pressure of liquid
3. Area of mouthpiece
4. Length of mouthpiece

Answer 1

Correct Answer - Option 4 : Length of mouthpiece

Concept: -

Mouthpiece: -

A mouthpiece is a short length of a pipe which is two or three times its diameter.

These can be classified as –

1. External mouthpiece (if fitted externally)

2. Internal mouthpiece (if fitted internally)

The internal mouthpiece can further be classified as running full type internal mouthpiece and running free type internal mouthpiece.

The following table shows the values of C_c, C_d and C_v for different types of mouthpieces –

Type of mouthpiece	Cc	CV	Cd
1. External mouthpiece	1.0	0.855	0.855
2. Running full type   internal mouthpiece	1.0	0.707	0.707
3. Running free type   internal mouthpiece	0.50	1.0	0.50