A LASER is a source of very intense, monochromatic, and a unidirectional beam of light. These properties of laser light can be exploited to measure long distances. The distance of the Moon from the Earth has been already determined very precisely using a laser as a source of light. A laser light beamed at the Moon takes 2.56 s to return after reflection at the Moon’s surface. How much is the radius of the lunar orbit around the Earth?

(1) 2.14×108 m

(2) 2.84×108 m

(3) 3.84×108 m

(4) 3.14×108 m

Subtopic:  Measurement & Measuring Devices |
 55%
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NEET 2023 - Target Batch - Aryan Raj Singh
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A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects underwater. In a submarine equipped with a SONAR, the time delay between the generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0 sec. What is the distance of the enemy submarine? (Speed of sound in water = 1450 m/s )

(1) 60.32 km

(2) 57.70 km

(3) 44.23 km

(4) 55.80 km

Subtopic:  Measurement & Measuring Devices |
 57%
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NEET 2023 - Target Batch - Aryan Raj Singh
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The farthest objects in our Universe discovered by modern astronomers are so distant that light emitted by them takes billions of years to reach the Earth. These objects (known as quasars) have many puzzling features, which have not yet been satisfactorily explained. What is the distance in km of a quasar from which light takes 3.0 billion years to reach us? 

1 3.2×1022 km
2 3.7×1022 km
3 2.8×1022 km
4 2.1×1022 km

Subtopic:  Measurement & Measuring Devices |
 53%
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NEET 2023 - Target Batch - Aryan Raj Singh
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The base quantity among the following is 

(1) Speed 

(2) Weight 

(3) Length 

(4) Area 

Subtopic:  Dimensions |
 84%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Which of the following is not a unit of time?

(1) Second 

(2) minute 

(3) hour 

(4) light year

Subtopic:  Dimensions |
 88%
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NEET 2023 - Target Batch - Aryan Raj Singh
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One astronomical unit is a distance equal to 

(1) 9.46×1015 m

(2) 1.496×1011 m

(3) 3×108 m

(4) 3.08×1016 m 

Subtopic:  Measurement & Measuring Devices |
 62%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Ampere second is a unit of 

(1) Current 

(2) Charge 

(3) Energy 

(4) Power 

Subtopic:  Dimensions |
 70%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Which of the following is a units that of force?

(1) N m 

(2) mN

(3) nm 

(4) n S

Subtopic:  Dimensions |
 53%
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NEET 2023 - Target Batch - Aryan Raj Singh
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The value of 60° in radian is 

(1) π2 

(2)  π3  

(3) π4 

(4)  π5

Subtopic:  Dimensions |
 88%
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NEET 2023 - Target Batch - Aryan Raj Singh
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The total plane angle subtended by a circle at its centre is 

(1) π rad 

(2)  2π rad 

(3) 2π3rad  

(4) π2rad

 

Subtopic:  Dimensions |
 79%
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