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Elite Icon Academy /Class 12 Physics Most Important Questions Answers for Maharashtra Board HSC 2026.1-Mark Questions + Answers (MCQs)

Soft iron core in transformer is used because it has
👉 (a) low coercivity and low retentivity.
SelfStudys

At resonance in a series LCR circuit, impedance equals:
👉 the resistance.
SelfStudys

In a BJT, largest current flows through:
👉 the emitter.
SelfStudys

Photoelectric cell: stopping potential × charge equals:
👉 max kinetic energy of emitted electrons.
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Which proves light is transverse?
👉 Polarization.
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Capacitance when separated plates move apart (isolated):
👉 capacitance decreases, charge stays same, potential increases.
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In potentiometer, at balance point current drawn from:
👉 neither cell nor auxiliary battery.
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📘 Short Question Answers
🔹 Define & Explain

Magnetic shielding
👉 Use of high-permeability material to protect from stray magnetic fields.
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Viscous drag
👉 Force of fluid friction opposing motion of an object through fluid.
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Thermal equilibrium
👉 When no net heat flow occurs and temperature is uniform.
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Isothermal process
👉 Process where temperature remains constant.
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🔹 Concept-Based Short Answers

Why base of transistor is thin & lightly doped?
👉 So electrons injected by emitter reach collector without recombining.
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State two applications of Pascal’s law:
👉 Hydraulic car lift & hydraulic brakes.
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Why tuning fork resonates with closed but not open pipe initially?
👉 Fundamental frequency of closed pipe is half that of open for same length.
SelfStudys

📈 2–3 Mark + Numerical Questions

Resonant frequency of LC circuit:
👉 For L = 5 H, C = 5 F →

𝑓
=
1
2
𝜋
𝐿
𝐶
=
1
2
𝜋
25
≈
0.032
f=
2π
LC
​

1
​

=
2π
25
​

1
​

≈0.032 Hz
CollegeDekho

Define inductive reactance, capacitive reactance, impedance:
👉
•
𝑋
𝐿
=
2
𝜋
𝑓
𝐿
X
L
​

=2πfL,
•
𝑋
𝐶
=
1
/
(
2
𝜋
𝑓
𝐶
)
X
C
​

=1/(2πfC),
•
𝑍
=
𝑅
2
+
(
𝑋
𝐿
−
𝑋
𝐶
)
2
Z=
R
2
+(X
L
​

−X
C
​

)
2
​

.
CollegeDekho

Diagram + setup for photoelectric effect:
👉 Cathode illuminated by light → electrons emitted → stopping potential applied to collector to measure KE.
CollegeDekho

📖 3–4 Mark / Long Questions

Young’s Double Slit Experiment + fringe width derivation:
👉 Derive
𝛽
=
𝐷
𝜆
𝑑
β=
d
Dλ
​

, where D = distance to screen, λ = wavelength, d = slit separation.
Careers360

Magnetic Dipole Moment Expression:
👉 For a coil:

𝜇
=
𝑁
𝐼
𝐴
μ=NIA, where N = turns, I = current, A = area. Calculate if given N = 300, diameter = 14 cm, I = 15 A.
CollegeDekho

Eddy Currents:
👉 Undesirable because they cause energy loss → minimized by using laminated cores.
CollegeDekho

Calculate De-Broglie Wavelength:
👉
𝜆
=
ℎ
𝑚
𝑣
λ=
mv
h
​

for given bullet/mass/speed