1. If V1 is the jet velocity and V0 is the vehicle velocity, then propulsive efficiency of a turbo-jet engine is
2. Theoretically, a four stroke cycle engine should develop __________ power as that of a two stroke cycle engine.
A. half
B. same
C. double
D. four times
3. Lightweight substances cannot be effective moderators.
A. True
B. False
4. The higher combustion chamber wall temperature in compression ignition engines will __________ knocking tendency.
A. increase
B. reduce
C. not effect
5. The nuclear radiators produced in a reactor which must be shielded are
A. electrons
B. α, β and γ rays
C. neutron and gamma rays
D. none of these
6. A two stroke cycle engine gives __________ mechanical efficiency than a four stroke cycle engine.
A. higher
B. lower
7. The delay period in compression ignition engines depends upon
A. temperature and pressure in the cylinder at the time of injection
B. nature of the fuel mixture strength
C. relative velocity between the fuel injection and air turbulence pressure of residual gases
D. all of the above
8. Lubrication in I.C. engines dissipates the heat generated from the moving parts due to friction.
A. True
B. False
9. The ratio of the heat equivalent to one kW hour to the heat in fuel per B.P. hour is termed as brake thermal efficiency.
A. Yes
B. No
10. The theoretically correct mixture of air and petrol is
A. 10:1
B. 15:1
C. 20:1
D. 25:1