Atoms — Physics STD 12 Science — Question

If intensity of incident light is increased in PEE then which of the following is true

(a) Maximum K.E. of ejected electron will increase

(b) Work function will remain unchanged

(c) Stopping potential will decrease

(d) Maximum K.E. of ejected electron will decrease

The internal resistance of a cell depends on

(a) The distance between the plates	(b) The area of the plates immersed
(c) The concentration of the electrolyte	(d) All the above

Energy of electron in a orbit of H-atom is

(a) Positive

(b) Negative

(c) Zero

(d) Nothing can be said

Which experiment seemed to make it clear that light propogates as a wave?

The velocity of photon is proportional to (where n is frequency)

(a)

(b)

(c)

(d) n

The output of a NAND gate is 0

(a) If both inputs are 0

(b) If one input is 0 and the other input is 1

(c) If both inputs are 1

(d) Either if both inputs are 1 or if one of the inputs is 1 and the other 0

If the electric force between two unknown charges is attractive, identify which of the following statement must be true?

A prism having an apex angle 4^o and refraction index 1.5 is located in front of a vertical plane mirror as shown in figure. Through what total angle is the ray deviated after reflection from the mirror

(a) 176o

(b) 4o

(c) 178o

(d) 2o

Some electric bulbs are connected in series across a 220 V supply in a room. If one bulb is fused then remaining bulbs are connected again in series across the same supply. The illumination in the room will

(a) Increase

(b) Decrease

(c) Remains the same

(d) Not continuous

A rocket is going away from the earth at a speed 0.2c, where c = speed of light. It emits a signal of frequency 4 . What will be the frequency observed by an observer on the earth

(a) 4

(b) 3.2

(c) 3

(d) 5