Physics - Online Test
Q1. The time period of a simple pendulum is given by ( l is length of pendulum and g the acceleration due to gravity)
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. Interference effects of light from two sources can be observed if
Answer : Option C
Explaination / Solution:
If the two sources are coherent, then the phase difference φ at any point will not change with time and we will have a stable interference pattern; i.e., the positions of maxima and minima will not change with time.
Q3. magnetic declination and dip refer to
Answer : Option B
Explaination / Solution:
No Explaination.
Q4. In Cavendish’s experiment,
Answer : Option D
Explaination / Solution:
Cavendish's apparatus for experimentally determining the value of G involved a light, rigid rod about 2-feet long. Two small lead spheres were attached to the ends of the rod and the rod was suspended by a thin wire. When the rod becomes twisted, the torsion of the wire begins to exert a torsional force that is proportional to the angle of rotation of the rod. The more twist of the wire, the more the system pushes backwards to restore itself towards the original position.
Q5. in p-type semiconductor the dopant is
Answer : Option D
Explaination / Solution:
The term p-type refers to the positive charge of the hole. In p-type semiconductors, holes are the majority carriers and electrons are the minority carriers. P-type semiconductors are created by doping an intrinsic semiconductor with acceptor impurities (or doping an n-type semiconductor).
Q6. Average speed is
Answer : Option A
Explaination / Solution:
Average speed is the absolute value of the average velocity or the magnitude of the velocity. Average Speed is always positive.
Q7. The speed of plane electromagnetic waves is maximum in
Answer : Option A
Explaination / Solution:
No Explaination.
Q8. If y(x, t) = a sin (kx + ωt + φ ) represents a wave function then ‘a’ is
Answer : Option A
Explaination / Solution:
In the equation
y(x, t) = a sin (kx + ωt + φ )
the term before trignometric function is called amplitude
Hence a (term before trignometric function) is the amplitude.
Q9. A moving conductor rod is 0.10 m long, and moves with a velocity of 2.5 m/s perpendicular to the magnetic field B of 0.60 T. If the circuit is completed with a resistance of 0.03Ω. Find the motional emf and the induced current.
Answer : Option B
Explaination / Solution:
e = Bvl = 0.60 x 2.5 x 0.1 = 0.15V
Q10. According to the Einstein’s model stopping potential for a metal having work function ϕ0 is given by
Answer : Option A
Explaination / Solution:
eV0=KmaxKmax=hν−ϕ0eV0=hν−ϕ0V0=(he)ν−ϕ0e
