Two lenses of power +10 D and - 5 D are placed in contact. Where should an object be held from the lens, so as to obtain a virtual image of magnification 2 ?

Two lenses of power 10D and -5D are placed in contact. Where should an object be held from the lens, so as to obtain a virtual image of magnification?

Derive the lens formula, (1)/(2)=(1)/(v)-(1)/(u) for a concave lens, using the necessary ray diagram. Two lenses of powers 10 D and -5 D are placed in contact. (i) Calculate the power of the new lens. (ii) Where should an object be held from the lens, so as to obtain a virtual image of magnification 2?

Derive the lens formula, (1)/(f)=(1)/(v)-(1)/(u) for a concave lens, using the necessary ray diagram. Two lenses of powers 10 D and -5 D are placed in contact. (i) Calculate the power of the new lens. (ii) Where should an object be held from the lens, so as to obtain a virtual image of magnification 2?

Where should an object be placed from a converging lens of focal length 10 c, so as to obtain a virtual image of magnification 2 ?

Two lenses of power + 10 D and - 5 D are placed in contact, (i) Calculate the focal length of the combination (ii) where should an object be held from the combination so as to obtain a virtual image of magnification 2 ?

Two lenses of power + 10 D and - 5 D are placed in contact, (i) Calculate the focal length of the combination (ii) where should an object be held from the combination so as to obtain a virtual image of magnification 2 ?

Two lenses of powers 10D - 5D are placed in contact Calculate the power of the new lens.

Where should an object be placed from a converging lens of focal length 20 cm, so as to obtain a real image of magnification 2?

Where should an object be placed from a converging lens of focal length 20 cm, so as to obtain a real image of magnification 2?