What is screeing of combinations?

What is the focal length of the combination if a lens of focal length - 70 c is brought in contact with a lens of focal length 150 cm? What is the power of the combination?

(a)Three resistors 1 Omega ,2 Omega and 3 Omega are combined in series. What is the total resis- tance of the combination? (b). If the combination is connected to a battery of emf 12 V and negligible internal resistance, obtain the potential drop across each resistor.

a.Three resistors 2Omega,4Omega and 5 Omega are combined in parallel. What is the total resis- tance of the combination? b. If the combination is connected to a battery of emf 20 V and negligible internal resistance, determine the current through each resistor and the total current drawn from the battery.

Rainbow is formed due to combination of

Decompostion reaction is the opposite of combination reaction .

In which of the following both pairs have correct combination?

In which of the following both pairs have correct combination?