Physics - Online Test
Q1. A thin insulated wire forms
a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli
ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm
respectively. The magnetic induction at the center of the spiral is
Answer : Option B
Explaination / Solution:
Q2. The primary use of a zener diode is
Answer : Option D
Explaination / Solution:
No Explaination.
Q3. The current i
flowing in a coil varies with time as shown in the figure. The variation of
induced emf with time would be
Answer : Option A
Explaination / Solution:
Q4. “Sky wax” is an application of nano product in the field of
Answer : Option C
Explaination / Solution:
No Explaination.
Q5. Consider an oscillator which has a charged particle and oscillates about its mean position with a frequency of 300 MHz. The wavelength of electromagnetic waves produced by this oscillator is
Answer : Option A
Explaination / Solution:
Q6. Stars twinkle due to,
Answer : Option C
Explaination / Solution:
No Explaination.
Q7. First
diffraction minimum due to a single slit of width 1.0×10–5 cm is at
30º. Then wavelength of light used is,
Answer : Option B
Explaination / Solution:
λ = a sin θ = 1 × 10-7 x sin 30° =500
Å
Q8. The total electric flux for
the following closed surface which is kept inside water
Answer : Option B
Explaination / Solution:
Q9. A photoelectric surface is illuminated successively by monochromatic light of wavelength λ and λ/2. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function at the surface of material is
Answer : Option D
Explaination / Solution:
Q10. Two wires of A and B with
circular cross section made up of the same material with equal lengths. Suppose
RA = 3 RB, then what is the ratio of radius of wire A to
that of B?
Answer : Option C
Explaination / Solution:
