Question

If an IC engine consumes fuel at the rate of 1 g/s and if the air-fuel ratio for it is 20, the mass flow rate of exhaust gas in g/s is:

1. 19
2. 21
3. 1
4. 20

Answer 1

Correct Answer - Option 2 : 21

Concept:

By Principle of conservation of mass we can have

m_a + m_f = m_e

where, m_a → mass flow rate of air into the cylinder, m_f → mass flow rate of fuel injected into the cylinder and m_e → mass flow rate of exhaust gas.

Calculation:

Given:

m_f = 1 g/s, air-fuel ratio → 20, therefore ma = 20 g/s

now, applying the conservation of mass we have

m_e = 20 + 1 = 21 g/s