8th Standard Science Chapter-5

Q11. Which of the following graph represents the correct variation of angle of incidence (i) and angle of deviation (δ)?

Q12. Figure a, b, c respectively; indicate the point in case of:

Q13. In which of the following cases will no dispersion take place when sunlight passes through it?

14. A: Astigmatism usually is caused by an irregularly shaped cornea.

B: Rainbow is the natural phenomenon in which dispersion takes place.

Q15. Having two eyes facilitates in:

A: Increasing the field of view

B: Bringing three dimensional view

C: Developing the concept of distance/size.

Then the correct option is/are:

Q11. Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them is in the ratio.

Q12. At a given time, a house is supplied with 100 A at 220 V. How many 75 W, 220 V light bulbs could be switched on in the house at the same time (if they are all connected in parallel)?

Q13. If the current flowing through a fixed resistor is halved, the heat produced in it will become:

Q14. You are given four ammeters A, B, C and D having least counts mentioned below:

(I) Ammeter A with least count 0.25 A

(II) Ammeter B with least count 0.5 A

(III) Ammeter C with least count 0.05 A

(IV) Ammeter D with least count 0.1 A

Which of the ammeters would you prefer for doing an experiment to determine the equivalent resistance of two resistances most accurately, when connected in parallel?

Q15. In the given figure, the resistors