Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics work and power commercial unit of energy power work and energy

$250 kg$ 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) $ 

  1. 6 horse power

  2. 7 horse power

  3. 8 horse power

  4. 9 horse power
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Power, $P = \dfrac{w}{t} = \dfrac{mgh}{t} =\dfrac{mgh}{t\times 746} HP = 8.35HP$
$\therefore Power$  $= 9HP$ 

Multiple choice physics work and energy commercial unit of energy power work and power

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

  1. (i) , (ii)

  2. (ii), (iii), (iv)

  3. (i), (ii), (iv)

  4. (i), (ii), (iii), (iv)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Using   $E = Pt$       $\implies$ Energy can be expressed in $Wh$

Using  $W = qV$     $\implies$ Energy can be expressed in $VC$
Using  $H = i^2Rt$  $\implies$ Energy can be expressed in $A^2\Omega s$
Whereas  Energy cannot be expressed by  $VAs^2$
Hence option C is correct.

Multiple choice physics work and energy commercial unit of energy power work and power

Electric energy supplied to homes is measured by

  1. voltmeter

  2. ammeter

  3. galvanometer

  4. kilowatt-hour meter
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The kilowatt hour (symbolized kW⋅h as per SI) is a composite unit of energy equivalent to one kilowatt (1 kW) of power sustained for one hour. One watt is equal to 1 J/s. One kilowatt hour is 3.6 MJoules, which is the amount of energy converted if work is done at an average rate of one thousand watts for one hour.

Multiple choice physics work and energy commercial unit of energy power work and power

1 kilowatt-hour is the amount of .... by 1000 watt electric appliance when it operates for one hour.

  1. Power

  2. Voltage

  3. Electric energy

  4. None
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

1 kilowatt-hour is the amount of energy energy consumed by a 1000 watt electric appliance when it is operated for one hour.

Multiple choice physics work and energy commercial unit of energy power work and power

Smallest commercial unit of energy is

  1. Kilowatt hour

  2. Watt second

  3. Watt hour

  4. Watt minutes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Smallest commercial unit of energy is called Watt hour. It is defined as the amount of electric energy, which flows through a conductor in one hour, at a power of one watt.

Multiple choice physics work and energy commercial unit of energy power work and power

Biggest commercial unit of energy.

  1. $kwh$
  2. $BOT$
  3. $kVAh$

  4. All
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The biggest commercial unit of energy is kilowatt hour $\left(kwh\right)$. It is also known as kilo-volt-ampere hour $\left(kVAh\right)$ and board of trade unit (BOT) or simply electric unit.