MCQs Load Factor, Demand Factor & Utilization Factor
Load factor of a power station is defined as:
(A) Maximum demand / Average load(B) Average load × Maximum demand
(C) Average load / Maximum demand ✅
(D) (Average load × Maximum demand)/172
Load factor of a power station is generally:
(A) Equal to unity(B) Less than unity ✅
(C) More than unity
(D) Equal to zero
The load factor of domestic load is usually:
(A) 10% to 15% ✅(B) 30% to 40%
(C) 50% to 60%
(D) 60% to 70%
Demand factor is defined as:
(A) Average load / Maximum load(B) Maximum demand / Connected load ✅
(C) Connected load / Maximum demand
(D) Average load × Maximum load
High load factor indicates:
(A) Cost of generation per unit power is increased(B) Total plant capacity is utilised for most of the time ✅
(C) Plant is not utilised properly
(D) None of the above
Power plant having maximum demand more than the installed capacity will have utilisation factor:
(A) Equal to unity(B) Less than unity
(C) More than unity ✅
(D) None of the above
In a power plant if the maximum demand is equal to plant capacity, then:
(A) Plant reserve capacity will be zero ✅(B) Diversity factor will be unity
(C) Load factor will be unity
(D) Load factor will be nearly 60%
MCQs on Load Curve & Diversity Factor
A load curve indicates:
(A) Average power used during the period(B) Average kWh (kW) energy consumption during the period ✅
(C) Either of the above
(D) None of the above
The area under a load curve gives:
(A) Average demand(B) Energy consumed ✅
(C) Maximum demand
(D) None of the above
Load curve is useful in deciding:
(A) Operating schedule of generating units(B) Sizes of generating units
(C) Total installed capacity
(D) All of the above ✅
Load curve of a power plant has always:
(A) Zero slope(B) Positive slope
(C) Negative slope
(D) Any combination ✅
For high value of diversity factor, a power station will supply:
(A) Less consumers(B) More consumers ✅
(C) Neither
(D) Either
Load curve helps in deciding:
(A) Total installed capacity(B) Sizes of generating units
(C) Operating schedule
(D) All of the above ✅
In a load curve the highest point represents:
(A) Peak demand ✅(B) Average demand
(C) Diversified demand
(D) None 🔷 3. Tariff System
MCQs on Tariff and Electricity Charges
Q1. The main objective of an electricity tariff is:
(A) To recover generation cost
(B) To recover transmission & distribution cost
(C) To ensure fair profit to utility
(D) All of the above ✅
Explanation: Tariff must recover all costs (generation, T&D, maintenance) and give profit.
Q2. Which of the following tariff types encourages consumers to use electricity during off-peak hours?
(A) Flat rate tariff
(B) Block rate tariff
(C) Time-of-day tariff ✅
(D) Two-part tariff
Explanation: Time-of-day tariff varies rate by time; lower rate during off-peak to shift load.
Q3. A two-part tariff is based on:
(A) Energy consumed and maximum demand ✅
(B) Fixed cost and fuel cost
(C) Load factor and diversity factor
(D) Peak and off-peak usage
Explanation: Two-part tariff = Fixed charge (based on kW/kVA) + Running charge (based on kWh).
Q4. The tariff in which per unit charge decreases with increase in consumption is called:
(A) Flat rate tariff
(B) Block rate tariff ✅
(C) Three-part tariff
(D) Time-of-day tariff
Explanation: Block rate tariff encourages higher use by offering cheaper rates for higher blocks.
Q5. Tariff that charges same rate per unit for all consumption is:
(A) Block rate tariff
(B) Flat rate tariff ✅
(C) Two-part tariff
(D) Time-of-day tariff
Explanation: Flat rate tariff is simple and easy – one rate per kWh irrespective of usage.
Q6. Which of the following is the disadvantage of flat rate tariff?
(A) Difficult to calculate
(B) Does not promote load factor improvement ✅
(C) Difficult to understand for consumers
(D) Depends on maximum demand
Explanation: Flat rate does not encourage users to control usage during peak hours.
Q7. Which tariff is best suited for industrial consumers with varying demand?
(A) Time-of-day tariff ✅
(B) Flat rate tariff
(C) Block rate tariff
(D) Uniform tariff
Explanation: Time-of-day tariff helps reduce cost by shifting load; ideal for industries.
Q8. In two-part tariff, the fixed charge depends on:
(A) Maximum demand ✅
(B) Energy consumed
(C) Load factor
(D) Type of load
Explanation: Fixed charge depends on the contracted demand (kW/kVA).
Q9. The ideal tariff system must be:
(A) Simple
(B) Fair to consumer and supplier
(C) Encourage efficient usage
(D) All of the above ✅
Explanation: An ideal tariff balances simplicity, fairness, and system efficiency.
Q10. The cost per unit of electricity is least in:
(A) Domestic load
(B) Industrial load ✅
(C) Commercial load
(D) Street lighting
Explanation: Industrial consumers have better load factor and higher consumption, reducing per-unit cost.
A consumer has to pay lesser fixed charges in:
(A) Flat rate tariff(B) Two part tariff
(C) Maximum demand tariff ✅
(D) Any of the above
In two part tariff, variation in load factor affects:
(A) Fixed charges(B) Operating charges ✅
(C) Maximum demand
(D) Any of the above
MCQs on Depreciation & Costs
Annual depreciation cost is calculated by:
(A) Sinking fund method(B) Straight line method
(C) Both (A) and (B) ✅
(D) None of the above
Depreciation charges are high in case of:
(A) Thermal plant ✅(B) Diesel plant
(C) Hydroelectric plant
Annual depreciation as per straight line method is calculated by:
(A) Capital cost / Number of years of life(B) (Capital cost − Salvage value) / Number of years of life ✅
(C) Increasing uniform sum with interest
(D) None of the above
Annual instalment towards depreciation reduces as interest increases in:
(A) Sinking fund depreciation ✅(B) Straight line depreciation
(C) Reducing balance depreciation
(D) None of the above
Annual depreciation proportional to earning capacity occurs in:
(A) Sinking fund depreciation(B) Straight line depreciation
(C) Reducing balance depreciation ✅
(D) None of the above
Salvage value of a plant is always:
(A) Positive(B) Negative
(C) Zero
(D) Any of the above ✅
Which of the following, in a thermal power plant, is not a fixed cost?
(A) Fuel cost ✅(B) Interest on capital
(C) Depreciation
(D) Insurance charges
With reference to a power station, which is not a fixed cost?
(A) Fuel cost ✅(B) Interest on capital
(C) Insurance charges
(D) Depreciation
In which power plant is maintenance cost usually high?
(A) Nuclear power plant(B) Hydroelectric power plant
(C) Thermal power plant ✅
(D) Diesel engine power plant
For a power plant, running cost includes:
(A) Cost of wages(B) Cost of fuel
(C) Cost of lubricants
(D) All of the above ✅
Which is not a method of estimating depreciation charges?
(A) Sinking fund method(B) Straight line method
(C) Diminishing value method
(D) Halsey’s 50—50 formula ✅ 🔷 Reserves in Power Plants
MCQs on Reserves in Power Plants
Reserved generating capacity not kept in operation but available in emergency is called:
(A) Hot reserve(B) Cold reserve ✅
(C) Spinning reserve
(D) Firm power
Generating capacity connected to bus bars and ready to take load is known as:
(A) Firm power(B) Cold reserve
(C) Hot reserve
(D) Spinning reserve ✅
________ is invariably used for peak load:
(A) Nuclear power plant(B) Steam turbine plant
(C) Pumped storage plant ✅
(D) None of the above
MCQs on Economics & Miscellaneous
Approximate estimation of power demand can be made by:
(A) Load survey method(B) Statistical methods
(C) Mathematical method
(D) Economic parameters
(E) All of the above ✅
Different generating stations use the following prime movers:
(A) Diesel engine(B) Hydraulic turbine
(C) Gas turbine
(D) Steam turbine
(E) Any of the above ✅
Diversity factor has direct effect on the:
(A) Fixed cost of unit generated ✅(B) Running cost of unit generated
(C) Both (A) and (B)
(D) Neither (A) nor (B)
Which of the following generating stations has minimum running cost?
(A) Nuclear(B) Hydro ✅
(C) Thermal
(D) Diesel
Annual operating expenditure of a power plant consists of:
(A) Fixed charges(B) Semi-fixed charges
(C) Running charges
(D) All of the above ✅
Maximum demand on a power plant is:
(A) Greatest of all short-time interval averaged demands ✅(B) Instantaneous maximum kVA supplied
(C) Both (A) or (B)
(D) None of the above
Which plants can generate power at unpredictable or uncontrolled times?
(A) Solar power plant(B) Tidal power plant
(C) Wind power plant
(D) Any of the above ✅
Direct conversion of heat into electric power is possible through:
(A) Fuel cell(B) Batteries
(C) Thermionic converter ✅
(D) All of the above
A low utilization factor indicates that:
(A) Plant is used for standby purpose only ✅(B) Plant is under maintenance
(C) Plant is used for base load only
(D) Plant is used for both peak and base load
Which of the following is not a source of power?
(A) Thermocouple ✅(B) Photovoltaic cell
(C) Solar cell
(D) Photoelectric cell
Ships are generally powered by:
(A) Nuclear power plants(B) Hydraulic turbines
(C) Diesel engines ✅
(D) Steam accumulators
Direct conversion of heat into electricity is possible through:
(A) Fuel cells(B) Solar cells
(C) MHD generators ✅
(D) None of the above
Which of the following places is not associated with nuclear power plants in India?
(A) Narora(B) Tarapur
(C) Kota
(D) Bangalore ✅
During load shedding:
(A) System power factor is changed
(B) Some loads are switched off ✅
(C) System voltage is reduced
(D) System frequency is reduced
Efficiency is of secondary consideration in:
(A) Base load plants
(B) Peak load plants ✅
(C) Both (A) and (B)
(D) None of the above
Power plant expected to have the longest life is:
(A) Steam
(B) Diesel
(C) Hydroelectric ✅
(D) Any of the above
Which plant cannot have a single unit of 100 MW?
(A) Hydroelectric
(B) Nuclear
(C) Steam
(D) Diesel ✅
Which equipment provides fluctuating load?
(A) Exhaust fan
(B) Lathe machine
(C) Welding transformer ✅
(D) All of the above
Increased load during summer months is due to:
(A) Increased business activity
(B) Increased water supply
(C) Increased use of fans and air conditioners ✅
(D) None of the above
Which of the following offers the highest electric load?
(A) Television set
(B) Toaster ✅
(C) Vacuum cleaner
(D) Washing machine
Essential requirement of peak load plant:
(A) It should run at high speed
(B) It should produce high voltage
(C) It should be small in size
(D) It should be capable of starting quickly ✅
In Hopkinson’s demand rate, the fixed charges depend on:
(A) Energy consumed
(B) Maximum demand ✅
(C) Both
(D) Neither
Ideal tariff for any consumer is:
(A) Two part tariff
(B) Three part tariff ✅
(C) Block rate tariff
(D) Any of the above
MCQs on Depreciation & Costs in Power System
Annual depreciation cost is calculated by:
(A) Sinking fund method
(B) Straight line method
(C) Both (A) and (B) ✅
(D) None of the above
Depreciation charges are high in case of:
(A) Thermal plant ✅
(B) Diesel plant
(C) Hydroelectric plant
Annual depreciation as per straight line method is calculated by:
(A) Capital cost / Number of years of life
(B) (Capital cost − Salvage value) / Number of years of life ✅
(C) Increasing uniform sum with interest
(D) None of the above
Annual instalment towards depreciation reduces as interest increases in:
(A) Sinking fund depreciation ✅(B) Straight line depreciation
(C) Reducing balance depreciation
(D) None of the above
Annual depreciation proportional to earning capacity occurs in:
(A) Sinking fund depreciation(B) Straight line depreciation
(C) Reducing balance depreciation ✅
(D) None of the above
Salvage value of a plant is always:
(A) Positive(B) Negative
(C) Zero
(D) Any of the above ✅
Which of the following, in a thermal power plant, is not a fixed cost?
(A) Fuel cost ✅(B) Interest on capital
(C) Depreciation
(D) Insurance charges
With reference to a power station, which is not a fixed cost?
(A) Fuel cost ✅(B) Interest on capital
(C) Insurance charges
(D) Depreciation
In which power plant is maintenance cost usually high?
(A) Nuclear power plant(B) Hydroelectric power plant
(C) Thermal power plant ✅
(D) Diesel engine power plant
For a power plant, running cost includes:
(A) Cost of wages(B) Cost of fuel
(C) Cost of lubricants
(D) All of the above ✅
Which is not a method of estimating depreciation charges?
(A) Sinking fund method(B) Straight line method
(C) Diminishing value method
(D) Halsey’s 50—50 formula ✅
MCQs on Reserves in Power Plants
Reserved generating capacity not kept in operation but available in emergency is called:
(A) Hot reserve(B) Cold reserve ✅
(C) Spinning reserve
(D) Firm power
Generating capacity connected to bus bars and ready to take load is known as:
(A) Firm power(B) Cold reserve
(C) Hot reserve
(D) Spinning reserve ✅
________ is invariably used for peak load:
(A) Nuclear power plant(B) Steam turbine plant
(C) Pumped storage plant ✅
(D) None of the above
MCQs on Economics & Miscellaneous
Approximate estimation of power demand can be made by:
(A) Load survey method(B) Statistical methods
(C) Mathematical method
(D) Economic parameters
(E) All of the above ✅
Different generating stations use the following prime movers:
(A) Diesel engine(B) Hydraulic turbine
(C) Gas turbine
(D) Steam turbine
(E) Any of the above ✅
Diversity factor has direct effect on the:
(A) Fixed cost of unit generated ✅(B) Running cost of unit generated
(C) Both (A) and (B)
(D) Neither (A) nor (B)
Annual operating expenditure of a power plant consists of:
(A) Fixed charges(B) Semi-fixed charges
(C) Running charges
(D) All of the above ✅
Maximum demand on a power plant is:
(A) Greatest of all short-time interval averaged demands ✅(B) Instantaneous maximum kVA supplied
(C) Both (A) or (B)
(D) None of the above
Which plants can generate power at unpredictable or uncontrolled times?
(A) Solar power plant(B) Tidal power plant
(C) Wind power plant
(D) Any of the above ✅
Direct conversion of heat into electric power is possible through:
(A) Fuel cell(B) Batteries
(C) Thermionic converter ✅
(D) All of the above
A low utilization factor indicates that:
(A) Plant is used for standby purpose only ✅(B) Plant is under maintenance
(C) Plant is used for base load only
(D) Plant is used for both peak and base load
Which of the following is not a source of power?
(A) Thermocouple ✅(B) Photovoltaic cell
(C) Solar cell
(D) Photoelectric cell
Ships are generally powered by:
(A) Nuclear power plants(B) Hydraulic turbines
(C) Diesel engines ✅
(D) Steam accumulators
Direct conversion of heat into electricity is possible through:
(A) Fuel cells(B) Solar cells
(C) MHD generators ✅
(D) None of the above
During load shedding:
(A) System power factor is changed(B) Some loads are switched off ✅
(C) System voltage is reduced
(D) System frequency is reduced
Efficiency is of secondary consideration in:
(A) Base load plants(B) Peak load plants ✅
(C) Both (A) and (B)
(D) None of the above
Power plant expected to have the longest life is:
(A) Steam(B) Diesel
(C) Hydroelectric ✅
(D) Any of the above
Which plant cannot have a single unit of 100 MW?
(A) Hydroelectric(B) Nuclear
(C) Steam
(D) Diesel ✅
Which equipment provides fluctuating load?
(A) Exhaust fan(B) Lathe machine
(C) Welding transformer ✅
(D) All of the above
Increased load during summer months is due to:
(A) Increased business activity(B) Increased water supply
(C) Increased use of fans and air conditioners ✅
(D) None of the above
Which of the following is not an operating cost?
(A) Maintenance cost(B) Fuel cost
(C) Salaries of high officials ✅
(D) Salaries of operating staff
Essential requirement of peak load plant:
(A) It should run at high speed(B) It should produce high voltage
(C) It should be small in size
(D) It should be capable of starting quickly ✅
Large capacity generators are invariably:
(A) Water cooled(B) Natural air cooled
(C) Forced air cooled
(D) Hydrogen cooled ✅