INSTRUCTIONS :
8 Q.1 to Q.7 are one mark question. (Very short answer / MCQ)
8 Q.8 is two marks question, to be answered in about 30 words.
8 Q.9 & Q.10 are three marks questions, to be answered in about 50 words.
8 Q.11 & Q.12 are five marks questions, to be answered in about 70 words.
1. White light is composed of ____________ colours.
(1) six (2) eight (3) seven (4) none of these
2. An image that cannot be obtained on a screen is called ________ image.
(1) real (2) virtual (3) point (4) none of these
3. The amount of heat produced in a electric wire depends on its
(1) material (2) length (3) thickness (4) all of these
4. Electric bell uses __________.
(1) bar magnets (2) electromagnets (3) natural magnets (4) none of these
5. The sideways reversal of the image by plane mirror is called _______.
(1) lateral inversion (2) regular reflection (3) diffuse reflection (4) none of these
6. Give one use of a concave mirror.
7. Name the safety device used to protect from short circuit.
8. Draw the circuit diagram to represent the circuit shown in figure.
9. David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m.
If he moves 1 m towards the mirror. What will be the distance between David and his image?
10. State any three characteristics of the image formed by a plane mirror.
11. State three differences between a convex mirror and a concave mirror.
12. Explain principle and working of electric bell ? Draw figure.
if you answer all the questions right and according to the instructions then I will make you the brainist promise
Answers
Answer:
1. seven
2. virtual
3. all of them above
4. electromagnetic
5. lateral inversion
6. It is used as reflector in torch, head light of automobiles
7. An electric fuse
9. 6m
10.The image formed by a plane mirror is a virtual image.
The image formed by a plane mirror suffers lateral inversion.
The image is formed as far behind the mirror as the object is in front of it.
11. (i)Convex mirrors have an outwardly bulging reflecting surface, and concave mirrors have an inwardly bulging reflecting surface.
(ii) Concave mirrors are those with an inward curve in the center that reflects light inward to focus it on a single focal point. Convex mirrors are those with an outward bulge in the center that allows light from the item to fall directly on it.
(iii) Concave - they produce a larger picture than the real size of the object. Convex mirrors, on the other hand, produce decreased images
12. Electric bell works on magnetic effect of electric current.
The switch is pressed and current flows through the circuit. The electromagnet is powered and generates a magnetic field that attracts the iron strip towards it. The striker strikes the gong (bell). When the striking arm strikes the gong, the contact is broken and the current stops flowing through the circuit.
(Electric bell diagram attached to this answer)
Q8 isn't the full question
