+2 Physics - Random One Mark Collection - Set 3

In continuation with our random collection of one mark questions covering Physics subject, questions from 11 to 20 are provided in this set. Have a good practice..

11) The r.m.S. value of an a.c. voltage with a peak value of 311 V is

a) 220 V
b) 110 V
c) 70.7 V
d) 50 V

12) The material through which electric charge can flow easily is

a) mica
b) quartz
c) copper
d) germanium

13) In the following nuclear reaction

14) The core used 1n audio frequency chokes is

a) carbon
b) lead
c) steel
d) iron

15) A photon of frequency $ is incident on a metal surface of threshold frequency $o. The kinetic energy of the emitted photoelectron is

a) h($-$o)
b) h$
c) h($+$o)
d) h$o

16) In an a.c. circuit with an inductor

a) voltage and current are In phase
b) voltage leads current by pi
c) current lags voltage by pi/2
d) voltage lags current by pi/2

17) The unit of Rydberg constant Is

a) no unit
b) m^-2
c) m^-1
d) m

18) In a plane diffraction grating the unit of grating element Is

a) metre
b) metre^-1
c) degree
d) no unit

19) In a Junction transistor the emitter region Is heavily doped since emitter has to supply to the base

a) majority carriers
b) minority carriers
c) acceptor ions
d) donor ions

20) The colour of light emitted by a LED depends on

a) amount of forward current
b) its reverse bias
c) its forward bias
d) type of semiconductor material