The question asks to identify the type of vehicle where a periscope is commonly used for external observation. A periscope is an optical instrument that allows observation from a concealed or protected position, typically over, around, or through an obstacle or object that prevents direct line-of-sight observation.
B) Submarine — Submarines operate underwater, and a periscope is essential for observing the surface (ships, aircraft, coastline) without surfacing completely. The periscope extends above the water while the submarine remains submerged, providing a crucial tactical advantage for stealth and reconnaissance.
The question asks for a civilian application of periscope-like technology. A periscope allows viewing objects that are not in the direct line of sight, typically by using mirrors or prisms to reflect light. We need to identify which option utilizes a similar principle for indirect viewing.
Correct Option: B) Backup cameras in cars. These cameras provide a view of the area behind the vehicle, which is otherwise obstructed from the driver's direct line of sight. This indirect viewing capability is functionally similar to the purpose of a periscope, which allows seeing over or around obstacles.
The question asks about the common material used for the body of a periscope. A periscope is an optical instrument that allows observation over, around, or through an object, or an obstacle. Its body needs to be durable, rigid, and often lightweight, especially for military or industrial applications.
Correct Option: C) Metal. Metal provides the necessary durability, rigidity, and protection for the optical components of a periscope, making it the most common and suitable material for its body.
The question asks to identify which military vehicle commonly uses a periscope for observation. A periscope is an optical instrument that allows observation from a concealed or protected position, typically by extending the line of sight over an obstacle.
A) Tank — Tanks are heavily armored vehicles where the crew operates from inside. Periscopes are essential for the crew (driver, gunner, commander) to observe the surroundings, aim weapons, and navigate without exposing themselves to direct enemy fire. This makes tanks a very common and direct answer to the question.
The question asks about the primary utility of a periscope in the context of trench warfare. We need to understand the function of a periscope and the conditions of trench warfare to determine its most significant application.
B) Observing enemy positions without exposure. This is the primary and most crucial role of a periscope in trench warfare. It enabled soldiers to gather vital intelligence on enemy activities, troop movements, and artillery placements while remaining safe from direct enemy fire. Without a periscope, observing above the trench would mean exposing oneself to immediate danger.
The question asks for a significant disadvantage of traditional periscopes. We need to evaluate each option based on the working principle and typical limitations of a traditional periscope.
C) Limited field of view — Traditional periscopes, especially the simpler ones, rely on a fixed optical path with mirrors or prisms. This design inherently restricts the angle of vision that can be observed at any given moment. To view a wider area, the periscope itself must be physically rotated, which means the instantaneous field of view remains narrow. This is a fundamental optical limitation.