Physics
Grade-7
Easy
Question
In the setup shown in the picture below, the sun rays are focused on a paper by a magnifying glass, which results in the paper catching fire. If the magnifying glass was replaced by a concave lens, the paper does not catch fire. Why?
- Concave lenses diverge the sun rays falling on them
- The sun rays are not concentrated on the paper at a point
- Concave lenses only form virtual images
- All of the above
The correct answer is: All of the above
Related Questions to study
Physics
A lens can only form a virtual, upright, and diminished images irrespective of the distance between the lens and the object. It is a ____ lens.
A lens can only form a virtual, upright, and diminished images irrespective of the distance between the lens and the object. It is a ____ lens.
PhysicsGrade-7
Physics
A concave lens forms a virtual, upright, and diminished image of an object ____.
A concave lens forms a virtual, upright, and diminished image of an object ____.
PhysicsGrade-7
Physics
The lens of a pair of spectacles used by a person is thinner in the middle and thicker towards the edges. The lens used in the spectacles is ____.
The lens of a pair of spectacles used by a person is thinner in the middle and thicker towards the edges. The lens used in the spectacles is ____.
PhysicsGrade-7
Physics
What kind of images does a convex lens not form?
What kind of images does a convex lens not form?
PhysicsGrade-7
Physics
A lens always forms a virtual, upright, and diminished image of an object placed in front of it. It is a ____ lens.
A lens always forms a virtual, upright, and diminished image of an object placed in front of it. It is a ____ lens.
PhysicsGrade-7
Physics
A light ray bends ____ on emerging from a ____.
A light ray bends ____ on emerging from a ____.
PhysicsGrade-7
Physics
Which of the given lenses can be used to light a fire?
Which of the given lenses can be used to light a fire?
PhysicsGrade-7
Physics
Which lens is used in a magnifying glass?
Which lens is used in a magnifying glass?
PhysicsGrade-7
Physics
When an object is moved too close to a convex lens, it forms a _____ image of that object.
When an object is moved too close to a convex lens, it forms a _____ image of that object.
PhysicsGrade-7
Physics
Except for normal incidence, the incident ray is ____ parallel to the corresponding emergent ray in case of refraction through a spherical lens.
Except for normal incidence, the incident ray is ____ parallel to the corresponding emergent ray in case of refraction through a spherical lens.
PhysicsGrade-7
Physics
During the normal incidence of a light ray on a spherical lens, the light ray ____.
During the normal incidence of a light ray on a spherical lens, the light ray ____.
PhysicsGrade-7
Physics
A light ray bends ____ on entering the air from ____.
A light ray bends ____ on entering the air from ____.
PhysicsGrade-7
Physics
When a parallel beam of light falls on a surface of a convex lens, it ____ the rays of light in it to a point called ____.
When a parallel beam of light falls on a surface of a convex lens, it ____ the rays of light in it to a point called ____.
PhysicsGrade-7
Physics
Concave lenses are ____ in the middle and ____ towards the edge.
Concave lenses are ____ in the middle and ____ towards the edge.
PhysicsGrade-7
Physics
Spherical lenses are _____ objects.
Spherical lenses are _____ objects.
PhysicsGrade-7
