The exercises you describe sound like very basic hip exercises. I often will prescribe standing on the affected leg to make it stabilize and get tired but more for the hip. As the other therapist noted, we don't know why you were prescribed these and what other factors such as pain, might be present.
If I feel an exercise is too easy and knowing the reason the patient is there, do not feel like I will aggravate the condition, I will push the patient. I also inform and expect the patient to let me know if it is to easy, or if pain is involved. If it is meniscal in nature, maybe you could ask about increasing the resistance by exercising on the table at your clinic or bed at home. By working against gravity, you are using force to lift the weight of your leg but again, sight unseen is hard to do.