UPSC Prelims Practice Questions — DRDO conducts successful flight-test of quasi-ballistic missile ‘Pralay’

Q1. With reference to the difference between cruise missiles and ballistic missiles, consider the following statements: Which of the statements given above are correct?

  1. A cruise missile receives almost continuous propulsion from its engine along a low, level flight path.
  2. Like a ballistic missile, a cruise missile is powered only during an initial boost phase and then glides to its target unpowered.
  3. Both cruise and ballistic missiles fly their entire path within the dense lower atmosphere.
  4. Because a cruise missile's engine breathes air, it needs atmospheric oxygen and so must fly within the atmosphere.
  • A. 1 and 4 only
  • B. 2, 3 and 4 only
  • C. 1, 3 and 4 only
  • D. 1 and 2 only

Q2. Consider the following statements: Which of the following is correct in respect of the above statements?

  1. During the later stages of a ballistic missile's boost phase, aerodynamic fins cannot be relied upon to steer it, so thrust-vector control is used instead.
  2. In the later stages of the boost phase, the missile is moving too slowly for its fins to produce useful control forces.
  • A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
  • B. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  • C. Statement-I is correct, but Statement-II is incorrect
  • D. Statement-I is incorrect, but Statement-II is correct

Q3. DRDO describes Pralay as a 'quasi-ballistic' surface-to-surface missile. Which one of the following best distinguishes a quasi-ballistic missile from a pure ballistic missile of comparable range?

  • A. It climbs to a higher apogee so that it stays above the atmosphere longer
  • B. It is driven by an air-breathing engine for the whole of its flight
  • C. It carries a heavier payload but over a shorter maximum range
  • D. It flies a lower, flatter trajectory and can manoeuvre during flight

Q4. A missile defence system tracks an incoming missile and computes where to intercept it. Suppose an attacker replaces a high-arcing ballistic missile with one of similar range that flies a lower, flatter trajectory and manoeuvres in flight. Consider the following likely consequences: Which of the statements given above is/are correct?

  1. Predicting the intercept point from the attacker's early track becomes less reliable.
  2. Exo-atmospheric interception becomes more suitable, since the attacker now spends more of its flight above the atmosphere.
  3. The burden of interception shifts towards defences that engage targets within the atmosphere.
  • A. 2 and 3 only
  • B. 1 and 3 only
  • C. 1, 2 and 3
  • D. 1 only

Q5. Consider the following assertion: A pure ballistic missile is, in principle, easier for a missile defence system to intercept than a quasi-ballistic missile of similar range. Consider the following statements: Which of the statements given above support/supports the assertion?

  1. A pure ballistic missile is powered throughout its flight, so its speed stays constant until impact.
  2. After its boost phase, a pure ballistic missile coasts along an arcing trajectory with only small corrections from its guidance system.
  3. Endo-atmospheric interceptors engage their targets within the atmosphere.
  • A. 2 and 3 only
  • B. 1, 2 and 3
  • C. 2 only
  • D. 1 and 2 only

Q6. Consider the following statements: Which of the following is correct in respect of the above statements?

  1. Solid-propellant motors are well suited to missiles that must be kept ready for launch over long periods.
  2. The thrust of a solid-propellant motor cannot be controlled in real time in the way a liquid-propellant engine's thrust can.
  • A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
  • B. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  • C. Statement-I is correct, but Statement-II is incorrect
  • D. Statement-I is incorrect, but Statement-II is correct

Q7. An army wants a road-mobile tactical missile that can be stored for long periods and fired soon after an order is given. In this context, consider the following statements about missile propulsion: Which of the statements given above is/are correct?

  1. In a solid-propellant motor, the motor case serves both as the container for the propellant and as its combustion chamber.
  2. If the mission required the engine to be shut down and restarted during flight, a liquid-propellant engine would be preferred.
  3. A solid-propellant motor needs pumps to feed propellant into its combustion chamber, which lengthens launch preparation.
  • A. 1, 2 and 3
  • B. 1 and 2 only
  • C. 1 and 3 only
  • D. 2 and 3 only

Q8. With reference to the Development-cum-Production Partner (DcPP) model used in DRDO missile programmes such as Pralay, consider the following statements: Which of the statements given above is/are correct?

  1. A defence public sector undertaking can act as a Development-cum-Production Partner for a DRDO-developed missile.
  2. Under the DcPP model, the developing DRDO laboratory hands over design responsibility to the partner, which then completes development on its own.
  • A. 1 only
  • B. 2 only
  • C. Both 1 and 2
  • D. Neither 1 nor 2