Physics - Online Test
Q1. Two slits are made one millimetre apart and the screen is placed one metre away. What is the fringe separation when bluegreen light of wavelength 500 nm is used?
Answer : Option B
Explaination / Solution:
No Explaination.
Q2. A cube-shaped permanent magnet is made of a feromagnetic matrerial with a magnetization M of about The side length is 2 cm. Magnetic field due to the magnet at a point 10 cm from the magnet along its axis is
Answer : Option B
Explaination / Solution:
No Explaination.
Q3.
A P– type crystal is obtained by doping
A) silicon with arsenic,
B) silicon with aluminum,
C) Ge with boron,
D) Ge with phosphorus.
Answer : Option A
Explaination / Solution:
Doping means the introduction of impurities into a semiconductor crystal to the defined modification of conductivity.
In P-Type Semiconductor, The addition of trivalent impurities such as boron, aluminum or gallium to an intrinsic semiconductor creates deficiencies of valence electrons,called "holes".
Q4. A truck is coming towards you from a distance of 1000m on a straight road, at time t=0. The driver stops for a second near a poster. He reaches you in 100 sec. The average speed in m/s is
Answer : Option A
Explaination / Solution:
Total distance covered s = 1000 m
Total time taken t = 100-0 = 100 s
Average speed
Q5. The velocity of sound in gas in which two waves of wavelength 1.0 m and 0.01 m produces 4 beats/sec. is
Answer : Option D
Explaination / Solution:
No Explaination.
Q6. 7.5 MHz to 12 MHz band corresponds to wavelength band of
Answer : Option A
Explaination / Solution:
No Explaination.
Q7. A rectangular wire loop of sides 8 cm and 2 cm with a small cut is moving out of a region of uniform magnetic field of magnitude 0.3 T directed normal to the loop. What is the emf developed across the cut if the velocity of the loop is 1 cm in a direction normal to the shorter side of the loop? For how long does the induced voltage last ?
Answer : Option A
Explaination / Solution:
duration of |e| is
Q8. Given h = 6.6 joule sec, the momentum of each photon in a given radiation is 3.3 kg metre/sec. The frequency of radiation is
Answer : Option C
Explaination / Solution:
λ=hpcν=hpν=pch=3.3×10−29×3×1086.6×10−34=1.5×1013Hz
Q9. Coaxial cables have a bandwidth in the range of
Answer : Option A
Explaination / Solution:
No Explaination.
Q10. An aircraft executes a horizontal loop of radius 1.00 km with a steady speed of 900 km/h. Compare its centripetal acceleration with the acceleration due to gravity.
Answer : Option B
Explaination / Solution:
Radius of the loop, r = 1 km = 1000 m
Speed of the aircraft, v = 900 km/h
=
Centripetal acceleration,
=
Acceleration due to gravity, g = 9.8 m/s2
= 6.4 g
