111) The radius of a coil of N turns is R. If the plane of the coil is placed parallel to a uniform magnetic field B, then the flux linked with the coil is
A) 
B) 
C) 
D) 0
112) The inductance L, Capacitance C and resistance R are the values of the components connected in series to an ac source of angular frequency ω. The inductive and capacitive reactances are 
and respectively. If the circuit is purely resistive, then
and 
respectively. If the circuit is purely resistive, thenA) L=C
B) 
C) 
D) R=L=C
View Answer
B)
Explanation:Pure resistive:
✔️ Answer: B
113) If the rate of change of electric field across the plates of a parallel plate capacitor is E and the displacement current is I, then the area of one plate of the capacitor is ( (\ \epsilon_0 \) is permittivity of free space)
A) 
B) 
C) 
D) 
View Answer
D)
Explanation:Displacement current:
So:
✔️ Answer: D
114) The work done to accelerate an electron from rest so that it can have a de Broglie wavelength of 6600 Å is nearly (Planck’s constant = Js and mass of electron = kg)
Js and mass of electron = 
kg)A) 
eV
B) 1.88 eV
C) J
D) 1.88 J
View Answer
C)
JExplanation:Solution:
Given:
λ = 6600 Å = 6.6 × 10⁻⁷ m
h = 6.6 × 10⁻³⁴ Js
m = 9 × 10⁻³¹ kg
Using:
λ = h / p ⇒ p = h / λ
Kinetic energy:
K = p² / (2m) = h² / (2mλ²)
Substitute:
K = (6.6×10⁻³⁴)² / [2 × 9×10⁻³¹ × (6.6×10⁻⁷)²] Cancel (6.6)²:
K = 10⁻⁶⁸ / (18 × 10⁻³¹ × 10⁻¹³)
= 10⁻⁶⁸ / (18 × 10⁻⁴⁴)
= (1/18) × 10⁻²⁴
≈ 5.56 × 10⁻²⁶ J
Convert to eV:
1 eV = 1.6 × 10⁻¹⁹ J
K ≈ (5.56×10⁻²⁶) / (1.6×10⁻¹⁹)
≈ 3.5 × 10⁻⁷ eV (very small)
Closest option (J form):
Final Answer:
(C) 5.56 × 10⁻²⁵ J
115) If the total energy of an electron in an orbit is positive, then
116) If 87.5% of atoms of a radioactive element decay in 6 days, then the fraction of atoms of the element that decay in 8 days is
A) 
B) 
C) 
D) 
View Answer
D)
Explanation:Half-life concept:
87.5% decay ⇒ 3 half-lives
8 days ⇒ 15/16 decayed
✔️ Answer: D
117) If the ratio of the mass numbers of two nuclei is 27:125, then the ratio of their surface areas is
View Answer
B) 9:25
Explanation:Surface area ∝
Ratio:
9:25
✔️ Answer: B
118) At absolute zero temperature, a semiconductor behaves like
119) Three logic gates are connected as shown in the figure. If the inputs are A=1, B=0 and C=1, then the values of , and respectively are
, 
and 
respectively are120) The radio horizon of a transmitting antenna of height 39.2 m is (Radius of the earth = 6400 km)
View Answer
C) 22.4 km
Explanation:Radio horizon:
Compute:
22.4 km
✔️ Answer: C
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