Work and Energy, Formula of Work, Unit of Work, What is Energy, Unit of Power.
Explore the dynamic relationship between work and energy at Nokryan.com, where you’ll find clear insights. We start by delving into the connection between “Work and Energy,” establishing a strong foundation for deeper comprehension. Moving on to “Formula of Work,” we present the mathematical equation that measures the transfer of energy when force is applied over a distance, offering a systematic approach to analysis. We then discuss “Unit of Work,” shedding light on the standard unit used for quantifying work performed, ensuring accuracy in calculations. Our goal at Nokryan.com is to make these intricate topics more understandable.
1. The SI unit of power is
- None of these
- Joule
- Pound
- Watt
correct
2. Work is defined as the dot product force and displacement which is a?
- Vector quantity
- Constant quantity
- None of these
- Scalar quantity
correct
3. Power is defined as?
- P = mV/t
- P = ∆W/Vt
correct - P = mt/V
- P = ∆V/∆t
4. The magnitude of work is?
- W = Fd
- W = df cos Ѳ
- W = Fd cos Ѳ
- None of thesecorrect
5. The field in which the work done be independent of the path followed is called?
- Conservative fields
correct - Non-conservative field
- None of these
- Varying intensity field
6. Power can also be defined as?
- P = F . W
- None of these
- P = F . A
- P = →F. →V
correct
7. An average energy used to make a car is?
- 7 x 10⁸ J
- 4 x 10⁷ J
- 8 x 10⁹ J
- 9 x 10⁹ J
correct
8. Which type of the following force cannot do work, acting on a body
- Frictional force
- Gravitational force
- Centripetal force
- Electric force
correct
9. A 70 kg man runs up a long height of stairs in 4.0 se. The vertical height of the stairs is 4.5 m. Calculate its power output in watts
- 7.2 x 10² W
- 7.3 x 10² W
- 7.7 x 10² Wcorrect
- 7.1 x 10³ W
10. Work done by a body when it covers some distance in suitable direction, may be?
- All of these
correct - Negative
- Positive
- Zero
11. SI unit of work is?
N-ms¯²- N-m²
- N-ms¯¹
- N-mcorrect
12. Approximate power of colour T.V. in watt is?
- 120
correct - 90
- 100
- 130
13. The work done by the body is maximum when it has angle
- 0⁰
correct - 90⁰
- 30⁰
- 60⁰
14. Kilowatt-hour is a unit of?
- None of these
- Electrical Energy
correct - Power
- Energy
15. One kilowatt hour is equal
- 3.6 x 10⁶ J
correct - 3.5 x 10⁶ J
- 3.6 x 10⁸ J
- 3.5 x 10⁵ J
16. No work is done by the body when angle between force and displacement is?
- 60⁰
- 45⁰
- 0⁰
- 90⁰
correct
17. The dimensions of work are
- ML²T¯²
correct - MLT¯²
- ML³T¯²
- MLT¯¹
18. Which of the following is conservative filed
- Electrostatic field
correct - Viscous field
- Frictional field
- All of these
19. Which of the following is non-conservative field?
- Frictional field
correct - Electrostatic field
- None of these
- Gravitational fields
20. Work done is a gravitational field along a closed loop is?
- Minimum
- Maximum
- 1
- Zero
correct
Entry Test 2021 Physics Work and Energy MCQS Online Preparation Sample Paper 2 Questions with Answer
1. Approximate power of a pocket calculator in watts
- 7.5 x 10²
- 7.5 x 10¯⁴
correct - 7.5 x 10¯²
- 7.5 x 10¯⁵
2. The escape velocity of Uranus in Kms¯¹
- 24.09
- 23.07
- 22.4
correct - 24.5
3. Approximate power of an electric heater in watts
- 2 x 10⁸
- 2 x 10⁵
- 2.1 x 10⁴
- 2 x 10³
correct
4. An average energy used by the car-from petrol in its life time
- 1 x 10¹⁰ J
- 1 x 10⁹ J
- 1 x 10¹¹ J
- 1 x 10¹² J
correct
5. The total work done in displacing a body from the surface of earth to infinite point is?
- W total = GMm/r₁
- W total = – GMm/ r₁correct
- W total = Gm/ r₁
- W total = GMm/ r₁²
6. The escape velocity of mercury in Kms¯¹
- 4.3correct
- 1.29
- 4.02
- 3.24
7. The escape velocity of Neptune in Kms¯¹
- 20.26
- 25.4
correct - 25.6
- 24.03
8. Approximate power of Jumbo. Let Aircraft in watts
- 1.2 x 10⁸
- 1.3 x 10⁸
correct - 1.2 x 10⁶
- 1.1 x 10⁹
9. The escape velocity Venus in Kms¯¹
- 8.24
- 10.4
correct - 5.28
- 10.02
10. Approximate power of flash light in watts: (2 cells)
- 1.56
- 1.5
correct - 1.55
- 1.2
11. The relation for the work energy principle is?
- None of these
- Vx² – Vy² = Fd
- ½ m Vy – ½ mvx = Fd
- 1/2mVf² – ½mVi² = Fdcorrect
12. All the food you eat in one day has the energy equivalent to petrol of?
- 1/5 liter
- 1/8 liter
- 1/3 liter
correct - 1/6 liter
13. The escape velocity of moon in Kms¯¹ is
- 1.23
- 2.59
- 2.40
correct - 2.43
14. The escape velocity of Mars in Kms¯¹
- 5.23
- 2.89
- 3.99
- 5.00
correct
15. Work energy principle is the work done on the body is equal to
Change in acceleration- Change in K.Ecorrect
- Change in power
- Change in angular velocity
16. The energy due to all the fossil fuels on the Earth is so small that, the energy reaching Earth in just days of sunlight which is?
- 30 days
- 10 days
correct - 5 days
- 60 days
17. Approximate power of a car moving at a speed of 90 kmh¯¹ in watts
- 1.4 x 10⁸
- 1.3 x 10⁷
- 1.2 x 10⁶
- 1.1 x 10⁵
correct
18. The escape velocity of Earth in Kms¯¹
- 9.75
- 11.2
correct - 15.6
- 12.3
19. The absolute gravitational potential energy of a body at a distance ‘r’ from the centre of the Earth
- U = GMm/ r²
- U = – GMm/r
correct - U = GMm/r
- None of these
20. The escape velocity of Saturn in Kms¯¹
- 37.4
- 37.0
correct - 30.0
- 35.04
Entry Test 2021 Physics Work and Energy MCQS Online Preparation Sample Paper 3 Questions with Answer
1. The renewable energy source is
- Biomass
correct - Tides
- None of these
- Natural gas
2. The initial velocity with which a body projected upward and never comes back is called?
- None of these
- Escape velocitycorrect
- Terminal velocity
- Kinetic energy
3. The average velocity of Jupiter in Kms¯¹
- 25
- 61.0
correct - 58.4
- 50
4. The relation for the escape velocity is?
- V esc = √2gRcorrect
- V esc = √2G/g
- V esc= √2GM/R₂
- V esc = √GM/R
5. The original source of tides is
- Ocean
- Earth
- Mooncorrect
- Sun
6. The tides are produced in the sea due to force which is?
- Gravitational force of mooncorrect
- Combine effect of both forces
- None of these
- Electromagnetic force of moon
7. The original source of biomass energy is
- None of these
- Moon
- Geothermal
- Sun
correct
8. The moon produce tidal effect in the sea by pulling
- Both
correct - None of these
- The sea
- The land
9. The original source of fossil fuels is?
- Biomass
- Geothermal
- None of these
- Sun
correct
10. The nonrenewable energy source is
Uranium
correct- Hydroelectric
- None of these
- Sunlight
11. The original source of solar energy is
- Stars
- Sun
correct - Earths
- Moon
12. When a body falls, its height decreases also its potential energy decreases. The expression is?
- h₁ – h₂ = 1/2 m ( V₁² – V₂²)
- mg(h₁ – h₂) = 1/2 m (V₂² – V₁²)
correct - mg(h₂ – h₁) = 1/2 m ( V₁² – V₂²)
- mg(h₁² – h₂²) = 1/2 m ( V₂² – V₁²)
13. The original source of hydroelectric is
- Watercorrect
- Sun
- Sind
- Moon
14. The original source of wind energy is
- Tides
- Waves
correct - Sun
- Moon
15. The original source of geothermal energy is
- Fossil fuels
- Biomass
- Moon
- Earth
correct
16. The original source of waves is
- Wind
- None of these
- Suncorrect
- Moon
17. The moon produces the raise the water in the sea roughly
- Twice a day
correct - Once a day
- None of these
- Several a day
18. Salter’s duck is consists of?
- Balance float
- Body float
- A and Ccorrect
- Duck float
19. By the pull of moon, the land up and down by as much as
- 10 cm
- 12 cm
- 16 cm
- 25 cm
correct
20. If it is assumed that a frictional force f is present, during the downward motion their?
- None of these
- mgh – f = ½ m²v
- mgh – f ½ mv²
correct - 2mgh – f = ½ mv²