Question

The most efficient engine is?
A. Petrol
B. Electric
C. Steam
D. Diesel

Answer 1

Hint:In order to solve this problem you need to know that an engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines, like the internal combustion engine, burn fuel to create heat which is then used to do work. Then we need to tell which engine’s efficiency is most among the petrol, electric, steam and diesel engine. Doing this will solve your problem.

Complete answer:
Here we need to tell the most efficient engine among petrol, electric, steam and diesel engines.
Petrol engine:- The petrol engine, also referred to as a diesel engine, is a spark-ignition internal combustion engine designed to run on petrol or diesel and related volatile fuels. Has lesser efficiency since more energy is removed as waste.
Electric engine:- It's the most powerful electric motor. To transform electricity into work, electric motors are very powerful. Physicists use abstract figures such as 90 percent, though figures are less than 40 percent when addressing combustion engines. But the efficiency of turning energy into motion can't be matched with the efficiency of moving gasoline into motion.
Steam engine:-On the Rankine cycle, which has a maximum Carnot efficiency of 63 percent for practical engines, steam engines and turbines operate with steam turbine power plants capable of achieving efficiency in the mid 40 percent range. The boiler was considered part of the engine in the earliest steam engines.
Diesel Engine:- In order to heat the air within, a diesel motor uses a much higher compression ratio inside the cylinder. The engine gets greater efficiency from the fuel because the air is so compressed. This means that, in general, a diesel engine is 20% more powerful than an identical petrol engine.
From the information above we get to know that efficiency of electric engines is most of all.

So, the correct option is B.

Note:
You need to know that efficiency can be determined by the formula energy exerted upon the absorbed energy in this issue. One also needs to know that by analysing the input and output energy, the efficiency of an automobile engine can be calculated. The percentage of efficiency is determined by contrasting the energy of the output, the kinetic energy is the case of the vehicle, the energy of the input, the energy found in the fuel molecules.