21. A water tank apperars shallower when it is viewed from top due to

1. 1. Rectilinear propagation of light

   
   
   

   2. Reflection

   
   
   

   3. Total internal reflection

   
   
   

   4. Refraction

   
   
   

---

1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: D

   N/A

---

22. Consider the following statements
    1. Light waves can travel in vacuum
    2. Light waves can be refracted
    3. Light waves are electro magnetic
    Which of the statements given above are correct?

1. 1. 1, 2 and 3

   
   
   

   2. 2 and 3 only

   
   
   

   3. 1 and 3 only

   
   
   

   4. 1 and 2 only

   
   
   

---

1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: A

   N/A

---

---

23. Total internal reflection can occur when light tends to pass from

1. 1. A denser to a rarer medium

   
   
   

   2. A rarer to a denser medium

   
   
   

   3. One medium to another of equal refractive index

   
   
   

   4. None of the above

   
   
   

---

1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: A

   N/A

---

24. A convex mirror is used to form an image of a real object. The image

1. 1. Always lies between the pole and the focus

   
   
   

   2. I diminished in size

   
   
   

   3. is erect

   
   
   

   4. All of the above

   
   
   

---

1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: D

   N/A

---

---

25. The least distance of distinct vision is 25 cm. The focal length of a convex lens is 5 cm It can act as simple microscope of magnifying power

1. 1. 4

   
   
   

   2. 5

   
   
   

   3. 6

   
   
   

   4. none of these

   
   
   

---

1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: C

   N/A

---