RRB JE 2019 Exam: Physics Quiz [Light] | 4th February

Railway Board offers opulent and revered job posts to its aspirants. And it is not every year that we get the notification from Railway offering a good number of vacant seats to the multitude aspirants. But the last year 2018 brought a pleasant surprise with almost 1,27,278 seats to be filled by the valid candidates. Opportunity is here but you have to welcome it with a provident strategy. 

Q1. A cut diamond sparkles because of its
एक तराशा हुआ हीरा किस की वजह से चमकता है-
(a) hardness / कठोरता
(b) high refractive index / उच्च अपवर्तक सूचकांक
(c) emission of light by the diamond / हीरे द्वारा प्रकाश का उत्सर्जन
(d) absorption of light by the diamond / हीरे द्वारा प्रकाश का अवशोषण

Show Answer

Ans.(b)
Sol. Diamonds have a very high refractive index (about 2.42 compared to about 1.5 for glass). The amount of light reflected at an air/other material interface is related to the refractive index charge at the interface and the bigger the refractive index change, the more light is reflected. Thus, diamond reflects large amount of light and therefore, sparkles more.

Q2. Butter paper is an example of …….. object.
बटर पेपर ________ ऑब्जेक्ट का एक उदाहरण है
(a) a transparent / पारदर्शक
(b) a translucent / पारदर्शी
(c) an opaque / अपारदर्शी
(d) a luminous / प्रकाशमान

Show Answer

Ans.(b)
Sol. Butter paper is a translucent object as it allows light to pass through it partially, thus not providing clear vision. While, a transparent substance allows light to pass through it completely providing a clear vision. Whereas, an opaque substance is impenetrable to light. On the other hand, luminous objects emit their own light.

Q3. A vibrating body
एक कांपता हुआ शरीर
(a) will always produce sound / हमेशा ध्वनि उत्पन्न करेगा
(b) may or may not produce sound if the amplitude of vibration is low / कंपन का आयाम कम होने पर ध्वनि उत्पन्न कर भी सकता है और नहीं भी
(c) will produce sound which depends upon frequency / ध्वनि उत्पन्न करेगा जो आवृत्ति पर निर्भर करता है
(d) None of these /इनमें से कोई नहीं

Show Answer



Ans.(c)
Sol. A vibrating body will produce sound which is dependent upon the frequency. Sounds of frequencies less than about 20 vibrations per second (20 Hz) cannot be detected by the human ear. Such sounds are called inaudible. On the higher side, sounds of frequencies higher than about 20,000 vibrations per second (20 kHz) are also not audible to the human ear.

Q4. The special technique used in ships to calculate the depth of ocean beds is
महासागरों की गहराई की गणना के लिए जहाजों में प्रयुक्त विशेष तकनीक है
(a) LASER
(b) SONAR
(c) sonic boom / ध्वनि बूम
(d) reverberation/ प्रतिध्वनि
Show Answer

 
Ans.(b)
Sol. SONAR or sound Navigation and Ranging is helpful for exploring and mapping the ocean because sound waves travel farther in the water than do radar and light waves. These also determine the time between the emission of sound pulse and its reception, the transducer can determine the range and orientation of the object.
While, LASER is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Whereas, sonic boom is the sound associated with the shock waves created by an object travelling through the air faster than the speed of sound. On the other hand, reverberation is the prolongation of a sound.

 

Q5. The reason of mirage is
मिराज का कारण है:
(a) Interference of light / प्रकाश का हस्तक्षेप
(b) Diffraction of light / प्रकाश का विवर्तन
(c) Polarization of light / प्रकाश का ध्रुवीकरण
(d) Total internal reflection of light / प्रकाश का कुल आंतरिक प्रतिबिंब

Show Answer

Ans.(d)
Sol. Mirage is an optical illusion. The reason of mirage is total internal reflection of light. In summer air near the ground is hotter and hence rarer than the air above which is responsible for TIR, hence, mirage is formed.

 

Q6. The color of light is determined by its
प्रकाश का रंग किसके द्वारा निर्धारित किया जाता है
(a) Amplitude/आयाम
(b) Wavelength/तरंग दैर्ध्य
(c) Intensity/तीव्रता
(d) Velocity/वेग

Show Answer


Ans.(b)
Sol. Wavelength is the distance between two points of the wave in the same phase. It is related to frequency and energy of the radiations. It helps in determining colour of light waves. The wavelength of light visible to eye falls between 400nm to 800nm.


Q7. Ultrasonic are sound waves of frequency
अल्ट्रासोनिक ध्वनि तरंगों की आवृत्ति ________ होती हैं.
(a) Greater than 20,000 Hz /20,000 हर्ट्ज से अधिक
(b) Less than 10,000 Hz / 10,000 हर्ट्ज से कम
(c) Equal to 1000 Hz /1000 हर्ट्ज के बराबर
(d) None of these / इनमे से कोई नहीं

Show Answer

Ans.(a)
Sol. Ultrasonics are sound waves of frequency greater than 20,000 Hz. The frequency range 20Hz to 20,000 Hz is human audible range of frequency.

Q8. Laser is a device for producing
लेजर _________ उत्पादन के लिए एक उपकरण है
(a) spontaneous radiation / सहज विकिरण
(b) dispersed radiation / फैलाव विकिरण
(c) scattered radiation / बिखरे हुए विकिरण
(d) stimulated radiation / उत्तेजित विकिरण

Show Answer
Ans.(d)
Sol. Laser (Light Amplification by Stimulated Emission of Radiation) is a device for producing stimulated radiation. In stimulated radiation, an incoming photon of a specific frequency can interact with an excited atomic electron causing creation of a new photon identical in all respect to the incident photon.
As a result, two similar waves (original incident wave and the newly formed one) constructively interfere, leading to a more intense wave.



Q9. What type of electromagnetic radiation is used in the remote control of a television?
टेलीविज़न के रिमोट कंट्रोल में किस प्रकार के विद्युत चुम्बकीय विकिरण का उपयोग किया जाता है?
(a) Infrared / इन्फ़रा रेड
(b) Ultraviolet / पराबैंगनी
(c) Visible / दर्शनीय
(d) None of these /इनमें से कोई नहीं

Show Answer

Ans.(a)
Sol. Infrared is used in the remote control of a television. It has wavelength greater than visible light (>800nm) which is invisible to human eye but can be felt as heat.


Q10. A 100 watt bulb is kept switched ON for four hours. The units of electrical energy consumed is
4 घंटे के लिए 100 वाट का एक इलेक्ट्रिक बल्ब का उपयोग किया जाता है. उपयोग की गई बिजिली की ऊर्जा की इकाई है:
(a) 400 unit / इकाई
(b) 25 unit / इकाई
(c) 4 unit / इकाई
(d) 0.4 unit / इकाई

Show Answer

Ans.(d)
Sol. One unit of electrical energy
= 1 kwh.
= 1 kilo watt hour
= 100/1000 kilo watt × 4 hour
= 0.4 unit

 

You may also like to read:

Download Upcoming Government Exam Calendar 2021

×

Download success!

Thanks for downloading the guide. For similar guides, free study material, quizzes, videos and job alerts you can download the Adda247 app from play store.

Thank You, Your details have been submitted we will get back to you.

Leave a comment

Your email address will not be published. Required fields are marked *

Join India largest learning distination

What You Will get ?

  • Job Alerts
  • Daily Quizes
  • Subject-Wise Quizes
  • Current Affairs
  • previous year question papers
  • Doubt Solving session

Login

OR

Forgot Password?

Join India largest learning distination

What You Will get ?

  • Job Alerts
  • Daily Quizes
  • Subject-Wise Quizes
  • Current Affairs
  • previous year question papers
  • Doubt Solving session

Sign Up

OR
Join India largest learning distination

What You Will get ?

  • Job Alerts
  • Daily Quizes
  • Subject-Wise Quizes
  • Current Affairs
  • previous year question papers
  • Doubt Solving session

Forgot Password

Enter the email address associated with your account, and we'll email you an OTP to verify it's you.


Join India largest learning distination

What You Will get ?

  • Job Alerts
  • Daily Quizes
  • Subject-Wise Quizes
  • Current Affairs
  • previous year question papers
  • Doubt Solving session

Enter OTP

Please enter the OTP sent to
/6


Did not recive OTP?

Resend in 60s

Join India largest learning distination

What You Will get ?

  • Job Alerts
  • Daily Quizes
  • Subject-Wise Quizes
  • Current Affairs
  • previous year question papers
  • Doubt Solving session

Change Password



Join India largest learning distination

What You Will get ?

  • Job Alerts
  • Daily Quizes
  • Subject-Wise Quizes
  • Current Affairs
  • previous year question papers
  • Doubt Solving session

Almost there

Please enter your phone no. to proceed
+91

Join India largest learning distination

What You Will get ?

  • Job Alerts
  • Daily Quizes
  • Subject-Wise Quizes
  • Current Affairs
  • previous year question papers
  • Doubt Solving session

Enter OTP

Please enter the OTP sent to Edit Number


Did not recive OTP?

Resend 60

By skipping this step you will not recieve any free content avalaible on adda247, also you will miss onto notification and job alerts

Are you sure you want to skip this step?

By skipping this step you will not recieve any free content avalaible on adda247, also you will miss onto notification and job alerts

Are you sure you want to skip this step?