Here, A and B refer to.
- AInsulator, conductor.
- BConductor, insulator.
- CInsulator, insulator.
- DConductor, conductor.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

An eye specialist prescribes spectacles having a combination of convex lens of focal length 40 cm in contact with a concave lens of focal length 25 cm. The power of this lens combination in diopters is
|
(a) + 1.5 |
(b) – 1.5 |
(c) + 6.67 |
(d) – 6.67 |
The refractive index of water is 1.33. What will be the speed of light in water
|
(a) 3 |
(b) 2.25 |
(c) 4 |
(d) 1.33 |
The two waves represented by y1 = a sin(wt) and have a phase difference of
|
(a) 0 |
(b) |
(c) |
(d) |
The given figure shows the wave forms for two inputs A and B and that for the output Y of a logic circuit. The logic circuit is

|
(a) An AND gate |
(b) An OR gate |
(c) A NAND gate |
(d) An NOT gate |
With a change of load resistance of a triode, used as an amplifier, from 50 kilo ohms to 100 kilo ohms, its voltage amplification changes from 25 to 30. Plate resistance of the triode is
|
(a) 25 kW |
(b) 75 kW |
(c) 7.5 kW |
(d) 2.5 kW |