Commercial unit of energy - class-IX
Description: commercial unit of energy | |
Number of Questions: 35 | |
Created by: Ashok Pandey | |
Tags: work and energy physics work, energy and power work and power |
A two kilowatt motor pumps out water from a well 10 meter deep. The quantity of water pumped out per hour is ( g = 10 $m/s^2$)
If the heart pushes 1 cc of blood in one second under pressure 20000 $N/m^2$ the power of heart is:
The pump of a water pumping system uses $2.0\ kW$ of electrical power when raising water. The
pumping system lifts $16kg$ of water per second through a vertical height of $7.0\ m$.
What is the efficiency of the pumping system?
Choose the correct option.
In our household applications, commercial unit of electricity is used. One unit is equal to:
$250 kg$ of water per minute is to be drawn from a well $150 m$ deep. An electric pump of _______ can be used. $(g = 10 m/s^2) $
Which of the following can be used to express energy? Symbols have their usual meanings for the units of physical quantities.
(i) Wh (ii) VC (iii) VAs$^2$ (iv) A$^2\Omega$s
Electric energy supplied to homes is measured by
1 kilowatt-hour is the amount of .... by 1000 watt electric appliance when it operates for one hour.
Convert 1 kWh to SI unit of energy.
Smallest commercial unit of energy is
Convert $28.8 khJ$ into kilo watt hour.
Biggest commercial unit of energy.
Unit used in selling electrical energy to consumer.
Watt hour meter means
$1 kwh$ is equal to
A lamp rated 20w and an electric iron rated 50w are used for 2 hour everyday. Calculate the total energy consumed in 20 days.
One kilowatt hour is equal to
Number of KWh in 1Joule.
Calculate the number of Joules in 1KWh.
When we pay for our electricity bill, we are paying for the ____________.
$1kWh= $ _________?
Kilowatt-hour is the unit of :
Kilowatt hour is the unit of:
A body is moved along a straight line by a machine delivering a constant power. The distance moved by the body in time $t$ is proportional to :
A body is moving along a straight line delivering power given as P = at, then work (W) done is given for time 0 to t is
A force of $ 2\hat { i } +3\hat { j } +2kN $ acts on a body for 4 s and produces a displacement of $3\hat {i} +4\hat {j} +5 \hat {k} m $ calculate the power ?
A pump of $200W$ power is lifting $2kg$ water from an average depth of $10m$ in one second. Velocity of water delivered by the pump is :
A small diesel engine uses a volume of $1.5 \times 10^4\, cm^3$ of fuel per hour to produce a useful power
output of 40 kW. It may be assumed that 34 kJ of energy is transferred to the engine when it uses $1.0\, cm^3$ of fuel.
What is the rate of transfer from the engine of energy that is wasted?
A body projected vertically from the earth reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest :
1 kWh is equal to
Number of kilowatt-hours =$\dfrac { volt\times ampere\times time }{ 1000 } $. Then:
If 1 unit of electricity cost $0.20$, how much does it cost to switch on a heater marked $120 V$, $3 A$ for $90$ min?
A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude $P _{0}$. The instantaneous velocity of this car is proportional to:
$1$ kWh$=$ ______________J.