Dr. Raheja places a rat in a small cage where it learns to press a bar to obtain a food pellet. Obviously, Dr. Raheja is using a(n) to study learning.

Operant chamber/ Skinner box

Explanation:

Operant chamber also known as Skinner box was developed by B.F skinner in 1930s. Operant chamber are used to study the animal behavior and can be used to both operant and classical conditioning.

In an operant chamber, animal free-operant behaviour is studied through animal response to a stimulus (such as light or voice) and if the reponse was corrrect the animal would be provided with reward.

In the question, Dr. Raheja is using the operant chamber for study learning. The rat would get the food (reward) by pressing a bar (correct response).

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

there’s no image attached but i can if you want: )