UPSC Prelims Full Length Test - 23

Which among the following is / are correct statements?

1. The images produced by Concave Mirrors are always real images
2. The images produced by Flat Mirrors are always virtual images
3. Converging Lens can produce virtual as well as real images

Select the correct option from the codes given below:

Consider the following statements regarding AM and FM transmission quality:

1. The AM signals are more susceptible to noise.
2. The FM receiver locks itself to catch the stronger signal only.
3. The wavelength of AM waves is much higher in comparison to the FM waves.

Which of the above statements is/are correct?

Consider the following with regard to the measurement of acceleration due to gravity ('g') on Earth:

1. Different values of 'g' are observed at varying depths below Earth's surface
2. 'g' varies at different altitudes above sea level
3. 'g' changes with changes in longitude
4. 'g' is affected by latitude

Which of the above statements is / are correct?

Consider the following statements regarding objectives of using tubeless tyres in aircrafts:

1. They reduce the chances of the tyre detaching from the rim.
2. They enable better shock resistance.
3. They help withstand heat generated during operations.

Which of the above statements is / are correct?

Consider the following statements with reference to digital signatures in internet communication:

1. By using digital signature, a sender cannot deny a message which he or she has sent to a receiver.
2. Digital signature can be used as legal proof to ensure that the message was sent by a certain sender.
3. Digital signature is used for safe communication between two computers of a closed network.
4. Digital signatures are required to send all email messages.

Which of the above statements is / are correct?