NCERT MCQ CLASS-12 CHAPTER-3 | PHYSICS NCERT MCQ | CURRENT ELECTRICITY | EDUGROWN

In This Post we are  providing Chapter-3 Current Electricity NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON CURRENT ELECTRICITY

Question 1.
The speed at which the current travels in a conductor is nearly:
(a) 3 × 10⁴ ms^-1
(b) 3 × 10⁶ ms^-1
(c) 3 × 10⁸ ms^-1
(d) 3 × 10¹⁰ ms^-1

Answer: (a) 3 × 10⁴ ms^-1

Question 2.
The resistance of a human body is about:
(a) 12 Ω
(b) 120 Ω
(c) 12 KΩ
(d) 120 MΩ

Answer: (c) 12 KΩ

Question 3.
The number of electrons that constitute 1 A of current is:
(a) 6.25 × 10¹⁶
(b) 6.25 × 10¹⁷
(c) 6.25 × 10¹⁸
(d) 6.25 × 10¹⁹

Answer: (c) 6.25 × 10¹⁸

Question 4.
How many different resistances are possible with two equal resistors?
(a) 2
(b) 3
(c) 4
(d) 5

Answer: (b) 3

Question 5.
Given three equal resistors, how many different combinations (taken all of them together) can be made?
(a) 3
(b) 4
(c) 5
(d) 6

Answer: (b) 4

Question 6.
Specific resistance of alkali metals is mostly affected by:
(a) temperature
(b) pressure
(c) magnetic field
(d) volume

Answer: (a) temperature

Question 7.
The example of a non-ohmic resistance is:
(a) copper wire
(b) filament lamp
(c) carbon resistor
(d) diode

Answer: (d) diode

Question 8.
If a certain piece of copper is to be shaped into a conductor of minimum resistance, its length (L) and cross-sectional area (a) shall respectively be :
(a) L, 2A
(b) L2, 2A
(c) 2L, 2A
(d) 2l, A2

Answer: (b) L2, 2A

Question 9.
The specific resistance of a rod of copper as compared to that of thin wire of copper is :
(a) less
(b) more
(c) same
(d) depends upon the length and area of cross-section of the wire

Answer: (c) same

Question 10.
A wire of resistance 3 Ω is cut into three pieces, which are then joined to form a triangle. The equivalent resistance between any corners of the triangle is :
(a) 23 Ω
(b) 32 Ω
(c) 12 Ω
(d) 13 Ω

Answer: (a) 23 Ω

Question 11.
The length of a conductor is halved. Its resistance will be :
(a) halved
(b) doubled
(c) unchanged
(d) quadrupled

Answer: (a) halved

Question 12.
In the above question, the conductance:
(a) halved
(b) doubled
(c) unchanged
(d) quadrupled

Answer: (b) doubled

Question 13.
Siemen is the unit of:
(a) resistance
(b) conductance
(c) specific conductance
(d) None of these

Answer: (b) conductance

Question 14.
How much electric energy is consumed by a 100 W lamp used for 6 hours everyday for 30 days?
(a) 18 kJ
(b) 18 kWh
(c) 1.8 J
(d) None of these

Answer: (b) 18 kWh

Question 15.
Suppose H₁ is the heat generated per second in the filament of a 100 W, 250 V lamp and H₂ is the heat generated in the filament of a 200 W, 250 V lamp. Then H₁/H₂ is equal to:
(a) 1
(b) 2
(c) 12
(d) 14

Answer: (c) 12

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