72451. Which of the following fuel detonates readily ?
72452. A spark plug gap is kept from
72453. The injection of fuel by external source is not required in case of engines working on Otto cycle.
72454. The running cost of a petrol engine is __________ than that of a diesel engine.
72455. In a petrol engine, if diesel is used, then the engine will
72456. Number of working strokes per min. for a four stroke cycle engine are __________ the speed of the engine in r.p.m.
72457. The air standard efficiency of an I.C. engine depends on
72458. The mean effective pressure of a diesel engine having fixed compression ratio will __________ if cut off ratio decreases.
72459. The knocking tendency in spark ignition engines may be decreased by
72460. In a two stroke engine, the working cycle is completed in two revolutions of the crankshaft.
72461. A reactor capable of converting a fertile material into fissile isotopes is called regenerative reactor.
72462. Alpha-methyl-naphthalene (C11 H10) has a cetane number of
72463. In a petrol engine, the mixture has the lowest pressure at the
72464. Which of the following does not relate to a spark ignition engine ?
72465. The increase in intake temperature of internal combustion engines will __________ efficiency.
72466. The reflectivity depends upon
72467. The indicated power for multi-cylinder engine will be same as that of a single cylinder engine.
72468. In order to prevent knocking in spark ignition engines, the charge away from the spark plug should have
72469. The size of a reactor at which the chain reaction can be initiated (i.e. when system becomes critical) with just enough fissionable material (called critical mass of fuel) is known as critical size of reactor.
72470. The mechanical efficiency (ηm) of the engine is given by
72471. A gas engine has a swept volume of 300 cm3 and clearance volume of 25 cm3. Its volumetric efficiency is 0.88 and mechanical efficiency is 0.90. The volume of the mixture taken in per stroke is
72472. A supercharger receives air from the atmosphere surrounding the engine, compresses it to a higher pressure and then feeds it into the inlet valve of the engine.
72473. Iso-octane (C8H18) has octane number of
72474. The brake power is always greater than indicated power.
72475. An ignition coil in the spark ignition engines supplies __________ voltage to the spark plug.
72476. The operation of forcing additional air under pressure into the engine cylinder is known as
72477. The cylinder of a gas engine is made __________ than that of the petrol engine.
72478. The thermal efficiency of a petrol engine is __________ as compared to diesel engine.
72479. The compression ignition engines are governed by
72480. The delay period in oil engines increases with increase in the speed of engine.
72481. The specific fuel consumption per B.P. hour for a diesel engine is about
72482. The ignition quality of diesel oil is expressed by
72483. In a four stroke cycle petrol engine, the expansion
72484. A fuel of an octane number rating of 75 matches in knocking intensity as a mixture of
72485. A two stroke cycle engine gives __________ the number of power strokes as compared to the four stroke cycle engine, at the same engine speed.
72486. By higher octane number of spark ignition fuel, it is meant that the fuel has
72487. The spark ignition engines are governed by
72488. If petrol is used in a diesel engine, then
72489. The sensing element in the control system of nuclear reactors measure the __________ of the neutron flux in the reactor.
72490. If the temperature of intake air in internal combustion engine increases, then its efficiency will
72491. In a coil ignition system of petrol engines, a condenser is connected across the contact-breaker in order to
72492. Which of the following statement is correct regarding normal cetaine?
72493. Enriched uranium is required as a fuel in a nuclear reactor, if light water is used as moderator and coolant, because light water has
72494. As compared to air standard cycle, in actual working, the effect of variation in specific heats is to
72495. The __________ engines can work on very lean mixture of fuel.
72496. The ignition quality of petrol is expressed by
72497. The fuel valve in a four stroke cycle diesel engine
72498. In petrol engines, advancing of the spark timing will __________ the knocking tendency.
72499. The knocking tendency in compression ignition engines for a given fuel will be
72500. In a four stroke cycle engine, the sequence of operations is