A double convex lens has a focal length of \(25\) cm. The radius of curvature of one of the surfaces is double of the other. What would be the radii if the refractive index of the material of the lens is \(1.5?\)
1. | \(100\) cm, \(50\) cm |
2. | \(25\) cm, \(50\) cm |
3. | \(18.75\) cm, \(37.5\) cm |
4. | \(50\) cm, \(100\) cm |
A biconvex lens has power \(P.\) It is cut into two symmetrical halves by a plane containing the principal axis. The power of one part will be:
1. \(0\)
2. \(\frac{P}{2}\)
3. \(\frac{P}{4}\)
4. \(P\)
A car is moving on a straight road at a speed of 50 km/h and a truck is ahead of the car and having a large plane mirror fixed vertically on the back of the truck. Truck is running at a speed of 70 km/h. For a stationary observer standing between car and truck. What is the speed of the image of the car in the mirror?
(1) 40 km/h
(2) 70 km/h
(3) 20 km/h
(4) 90 km/h
Two plane mirrors should be placed at what angle so that the incident ray and final reflected ray are antiparallel?
1. 90
2. 60
3. 45
4. 30
The field of view is maximum for
(1) Concave mirror
(2) Convex mirror
(3) Plane mirror
(4) Parabolic concave mirror
An object is placed in front of a concave mirror. The distance of the object from the focus is 10 cm and the distance of the image from the focus is 40 cm, then the focal length mirror is :
1. 20 cm
2. 10 cm
3. 40 cm
4. 30 cm
A fish at a depth y inside the water is seeing a bird. The bird is at a height x above the water level. Refractive index of water is , then the apparent distance of the bird as seen by the fish is :
(1) x+y
(2) y+x
(3) x+
(4) y+
A jar of height H is half-filled with a liquid of refractive index and the remaining half with a liquid of refractive index . The apparent depth of a coin placed at the bottom of the jar when seen from the vertically upward direction is:
1.
2.
3.
4.
If the critical angle for a liquid A is 60 and critical angle for the liquid B is 45, then the critical angle for a ray traveling from A to B will be:
1. Less than 45
2. More than 60
3. Between 45 and 60
4. Does not exist
A convex lens made of 5 different transparent materials is used to make an image of an object placed in front of it. The number of images formed will be :
(1) 2
(2) 3
(3) 4
(4) 5