11th Physics - Book Back Answers - Unit 7 - English Medium Guides

 

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Tamil Nadu Board 11th Standard Physics - Unit 7: Book Back Answers and Solutions

    This post covers the book back answers and solutions for Unit 7 – Physics from the Tamil Nadu State Board 11th Standard Physics textbook. These detailed answers have been carefully prepared by our expert teachers at KalviTips.com.

    We have explained each answer in a simple, easy-to-understand format, highlighting important points step by step under the relevant subtopics. Students are advised to read and memorize these subtopics thoroughly. Once you understand the main concepts, you’ll be able to connect other related points with real-life examples and confidently present them in your tests and exams.

    By going through this material, you’ll gain a strong understanding of Physics Unit 7 along with the corresponding book back questions and answers (PDF format).

Question Types Covered:

• 1 Mark Questions: Choose the correct answer, Fill in the blanks, Identify the correct statement, Match the following 
• 2 Mark Questions: Answer briefly 
• 3, 4, and 5 Mark Questions: Answer in detail

All answers are presented in a clear and student-friendly manner, focusing on key points to help you score full marks.

All the best, Class 11 students! Prepare well and aim for top scores. Thank you!

Unit 7: Properties Of Matter

I. Multiple Choice Questions

1. Consider two wires X and Y. The radius of wire X is 3 times the radius of Y. If they are stretched by the same load then the stress on Y is
(a) equal to that on X
(b) thrice that on X
(c) nine times that on X
(d) Half that on X
Answer Key:
(c) nine times that on X

2. If a wire is stretched to double of its original length, then the strain in the wire is
(a) 1 
(b) 2
(c) 3 
(d) 4
Answer Key:
(a) 1 

3. The load – elongation graph of three wires of the same material are shown in figure. Which of the following wire is the thickest? 

(a) wire 1
(b) wire 2
(c) wire 3
(d) all of them have same thickness
Answer Key:
(a) wire 1

4. For a given material, the rigidity modulus is  of Young’s modulus. Its Poisson’s ratio is
(a) 0
(b) 0.25
(c) 0.3 
(d) 0.5
Answer Key:
(d) 0.5

5. A small sphere of radius 2cm falls from rest in a viscous liquid. Heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to
(NEET model 2018)

(a) 2²

(b) 2³

(c) 2⁴

(d) 2⁵

Answer Key:
(d) 2⁵

6. Two wires are made of the same material and have the same volume.The area of cross sections of the first and the second wires are A and 2A respectively. If the length of the first wire is increased by Δl on applying a force F, how much force is needed to stretch the second wire by the same
amount? (NEET model 2018)
(a) 2 F 
(b) 4 F
(c) 8 F 
(d) 16 F
Answer Key:
(b) 4 F

7. With an increase in temperature, the viscosity of liquid and gas, respectively will
(a) increase and increase
(b) increase and decrease
(c) decrease and increase
(d) decrease and decrease
Answer Key:
(c) decrease and increase

8. The Young’s modulus for a perfect rigid body is
(a) 0
(b) 1
(c) 0.5 
(d) infinity
Answer Key:
(d) infinity

9. Which of the following is not a scalar?
(a) viscosity
(b) surface tension
(c) pressure
(d) stress
Answer Key:
(d) stress

10. If the temperature of the wire is increased, then the Young’s modulus will
(a) remain the same
(b) decrease
(c) increase rapidly
(d) increase by very a small amount
Answer Key:
(b) decrease

11. Copper of fixed volume V is drawn into a wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is Δl. If Y represents the Young’s modulus, then which of the following graphs is a straight line? (NEET 2014 model)
(a) Δl versus V
(b) Δl versus Y
(c) Δl versus F
(d) Δl versus $\frac{1}{l}$
Answer Key:
(c) Δl versus F

12. A certain number of spherical drops of a liquid of radius R coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then
(a) energy = 4VT  is released 

(b) energy = 3VT $($$)$ is absorbed
(c) energy = 3VT $($$)$ is released
(d) energy is neither released nor absorbed
Answer Key:
(c) energy = 3VT $($$)$ is released

13. The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied?
(a) length = 200 cm, diameter = 0.5 mm
(b) length = 200 cm, diameter = 1 mm
(c) length = 200 cm, diameter = 2 mm
(d) length = 200 cm, diameter = 3 m
Answer Key:
(a) length = 200 cm, diameter = 0.5 mm

14. The wettability of a surface by a liquid depends primarily on
(a) viscosity
(b) surface tension
(c) density
(d) angle of contact between the surface and the liquid
Answer Key:
(d) angle of contact between the surface and the liquid

15. In a horizontal pipe of non-uniform cross section, water flows with a velocity of 1 ms^-1 at a point where the diameter of the pipe is 20 cm. The velocity of water (1.5 ms^-1) at a point where the
diameter of the pipe is (in cm)
(a) 8 
(b) 16
(c) 24 
(d) 32
Answer Key:
(b) 16

II. Short Answer Questions

11th physics

III. Long Answer Questions

11th Physics

IV. Exercise

11th Physics