7th Class Science Lights and Sound Question Bank

done Self Test-13

• question_answer1) A plain mirror forms a virtual image. The distance between Maria and her image in a plane mirror is 10 m. How much distance should she move in order to get the distance of 5 m between herself and her image?

  A) 2.5m away from the mirror

  B) 2.5 m towards the mirror

  C) 5m away from the mirror

  D) 5 m towards the mirror

  E) None of these

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• question_answer2) Spherical mirrors are widely used as a rear view mirror in the automobiles. Why the word AMBULANCE is differently painted in front of the hospital vans?

  A) It is accurately readable in front of the rear view mirror

  B) It reads erratic in front of the rear view mirror

  C) Only for word art

  D) All of these

  E) None of these

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• question_answer3) The automobiles require a heavy reflector. The headlight of the car is made up of which one of the following reflectors?

  A) Concave reflectors

  B) Convex reflectors

  C) Plane reflectors

  D) All of these

  E) None of these

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• question_answer4) The focal length of a concave mirror is 5 cm. Find its curvature.

  A) 2.5 cm

  B) 5 cm

  C) 10 cm

  D) All of these

  E) None of these

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• question_answer5) Small letters cannot be easily read. Which one of the following lenses is mostly used for the purpose?

  A) Concave lens

  B) Convex lens

  C) Plane lens

  D) All of these

  E) None of these

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• question_answer6) When a convex lens is used as a magnifying glass, then the object is placed at which one of the following distances from the lens?

  A) Distance less than the focal length

  B) Distance more than the focal length

  C) At focal point

  D) All of these

  E) None of these

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• question_answer7) Concave mirror is used to obtain a real, inverted image of the object. Which one of the following lenses is used for real inverted as well as the virtual and erect image?

  A) Concave lens

  B) Lens made by plain mirror

  C) Convex lens

  D) All of these

  E) None of these

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• question_answer8) In the physics lab, Merriam rotates Newton's colour dice rapidly. A boy is observing the experiment. What he has observed in this experiment?

  A) Seven colours of light looks like two colours of white and black

  B) Seven colours of light looks like single colour of black

  C) Seven colours of light looks like single colour of white

  D) All of these

  E) None of these

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• question_answer9) The formation of rainbow in the sky is due to the sun light. Which one of the following is involved for the formation of rainbow in the sky?

  A) Expansion of light

  B) Expansion of heat by the sun

  C) Distance between the earth and the moon

  D) Dispersion of light

  E) None of these

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• question_answer10) A rainbow in the sky is the spectrum of the colours How many colours are involved in the formation of a spectrum?

  A) Ten

  B) Seven

  C) Eight

  D) All of these

  E) None of these

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