### 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 these
**correct**

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 W
**correct** - 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-m
**correct**

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/ r₁
**correct** - W total = Gm/ r₁
- W total = GMm/ r₁²

6. The escape velocity of mercury in Kms¯¹

- 4.3
**correct** - 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 = Fd
**correct**

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.E
**correct** - 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 velocity
**correct** - 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 = √2gR
**correct** - V esc = √2G/g
- V esc= √2GM/R₂
- V esc = √GM/R

5. The original source of tides is

- Ocean
- Earth
- Moon
**correct** - Sun

6. The tides are produced in the sea due to force which is?

- Gravitational force of moon
**correct** - 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

- Water
**correct** - 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
- Sun
**correct** - 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 C
**correct** - 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