If V₁ is the jet velocity and V₀ is the vehicle velocity, then propulsive efficiency of a turbojet engine is

A

$$\frac{{{{\text{V}}_1}}}{{{{\text{V}}_0} + {{\text{V}}_1}}}$$

B

$$\frac{{{{\text{V}}_0}}}{{{{\text{V}}_0} + {{\text{V}}_1}}}$$

C

$$\frac{{2{{\text{V}}_0}}}{{{{\text{V}}_0} + {{\text{V}}_1}}}$$

D

$$\frac{{2{{\text{V}}_1}}}{{{{\text{V}}_0} + {{\text{V}}_1}}}$$

If V₁ is the jet velocity and V₀ is the vehicle velocity, then the propulsive efficiency of a rocket is given by

A

[2(V₀/V₁)]/ [1 + (V₀/V₁)²]

B

(V₀/V₁)/ [1 + (V₀/V₁)²]

C

V₀/(V₀ + V₁)

D

V₁/(V₀ + V₁)

If V₁ is the jet velocity and V₀ is the vehicle velocity, then the propulsive efficiency of a rocket is given by

A

$$\frac{{2\left( {\frac{{{{\text{V}}_0}}}{{{{\text{V}}_1}}}} \right)}}{{1 + {{\left( {\frac{{{{\text{V}}_0}}}{{{{\text{V}}_1}}}} \right)}^2}}}$$

B

$$\frac{{\frac{{{{\text{V}}_0}}}{{{{\text{V}}_1}}}}}{{1 + {{\left( {\frac{{{{\text{V}}_0}}}{{{{\text{V}}_1}}}} \right)}^2}}}$$

C

$$\frac{{{{\text{V}}_0}}}{{{{\text{V}}_0} + {{\text{V}}_1}}}$$

D

$$\frac{{{{\text{V}}_1}}}{{{{\text{V}}_0} + {{\text{V}}_1}}}$$

Consider the following statements with reference to Jet stream. 1. The Jet Stream is a geostrophic wind. 2. There are two permanent jet streams – subtropical jets at mid-latitudes and polar front jets at lower latitudes. 3. Temperature also influences the velocity of the jet stream. The lower the difference in air temperature, the faster the jet stream. Which of the statements given above is/are NOT correct?

A

1 and 2 only

B

2 and 3 only

C

1 and 3 only

D

1, 2, 3

The maximum propulsive efficiency of a turbojet engine is at a speed of

A

1000 km/h

B

2000 km/h

C

2400 km/h

D

3000 km/h

Why do vehicle tires experience a loss of traction, and slip during a rainy day on a wet road? a) Because during rainy day efficiency of the engine drops effectively b) Because during rainy day roads are normally wet and this reduces friction between car and vehicle. c) Because during rainy day roads are normally wet and this increases friction between car and vehicle and hence, we experience loss of traction and vehicle slips. Choose one of the following

A

Only option a is correct

B

Only option b is correct

C

Only option c is correct

D

Both option b and a are correct

A jet of water is striking at the centre of a curved vane moving with a uniform velocity in the direction of jet. For the maximum efficiency, the vane velocity is ________ of the jet velocity

A

One-half

B

One-third

C

Two-third

D

Three-fourth

In the question below, are given a statement followed by three courses of actions numbered I, II and III. On the basis of the information given, you have to assume everything in the statement to be true, and then decide which of the suggested courses of action logically follow(s) for pursuing. Statement: Soon you would not need to carry original copies of all vehicle papers like driving licence, vehicle registration certificate, insurance, pollution certificate or the permits issued to commercial vehicles with you. According to a ToI report, the Centre plans to amend Motor Vehicles Rules to make it legal for any citizen to carry digital vehicle documents and simultaneously making it compulsory for traffic police to accept digital version of documents. This means that you would not have to carry physical papers in your vehicle as digital copies of the certificates would be valid. Courses of action: I. The ministry has proposed installation of FASTags on the front windscreens. FASTag is a device that uses radio frequency identification (RFID) technology for making toll payments directly from the user account. II. To avail the facility, one has to store all the vehicle documents on the government's cloud-based service DigiLocker and when asked he/she can simply display the stored certificates on a smartphone or any other digital devices. These digital copies can be shared with other departments as identity and address proof. III. The government has increased the maximum load carrying capacity of heavy vehicles, including trucks, by 20-25 per cent besides scrapping the mandatory annual renewal of fitness certificates for freight carriers. Fitness certificates for trucks would now be renewed in every two years not annually. Which of the following course/courses of action can be said to be said to be a rudimentary course/courses of action?

A

Only III follows

B

Neither I nor III follows

C

None follows

D

All except III and II

E

All I, II and III follow

Air enters a turbojet engine at the rate of 40 kg/s with a velocity of 250 m/s relative to an aircraft which is moving at 300 km/hr. Exhaust of the engine has velocity of 700 m/s relative to the moving aircraft. The thrust developed by the engine is

A

24 kN

B

18 kN

C

12 kN

D

9 kN

In turbo fan engine, the jet velocity as compared to turbojet engine is

A

Less

B

More

C

Same

D

May be less or more depending upon speed

If V₁ is the jet velocity and V₀ is the vehicle velocity, then propulsive efficiency of a turbojet engine is

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