CBSE 12TH PHYSICS - Online Test
Q1. According to Huygens principle
Answer : Option B
Explaination / Solution:
No Explaination.
Q2. Far axial magnetic field of a solenoid as well as bar magnet vary
Answer : Option A
Explaination / Solution:
No Explaination.
Q3. doping of semiconductor is the process of
Answer : Option B
Explaination / Solution:
Doping is the process of adding impurities to intrinsic semiconductors to alter their properties. Normally Trivalent and Pentavalent elements are used to dope Silicon and Germanium. When an intrinsic semiconductor is doped with Trivalent impurity it becomes a P-Type semiconductor.
Q4. The direction of propagation of an electromagnetic plane wave is
Answer : Option B
Explaination / Solution:
No Explaination.
Q5. According to Farady's law
Answer : Option D
Explaination / Solution:
The induced electromotive force in any closed circuit is equal to the negative of the time rate of change of the magnetic flux enclosed by the circuit.
Q6.
In the above experimental set up for studying photoelectric effect, if keeping the frequency of the incident radiation and the accelerating potential fixed, the intensity of light is varied, then
Answer : Option D
Explaination / Solution:
With increase in intensity no. of photon incident increases. So that more electron emitted from metal and photo current increases with increase in intensity.
Q7. Transducer is a device that
Answer : Option B
Explaination / Solution:
Any device which converts energy from one form to another is called a transducer.It converts variation in physical quantities such as pressure,dispalcement,force,temprature etc.Like microphone converts sound signal into an electrical signal.
Q8. Two positive charges
Answer : Option B
Explaination / Solution:
Acc to coulomb's law unlike charges always attract each other while like charges always repel each other so between two positive charges repulsion is working.
Q9. In Geiger-Marsden experiment, at the point of closest approach
Answer : Option D
Explaination / Solution:
No Explaination.
Q10. Phasor diagrams show
Answer : Option D
Explaination / Solution:
By convention phasor diagrams are made to show the rotation of phasor in counterclockwise direction with constant speed
