Swami Vivekanand Junior College Physics 1st Semester Exam 2023-24 PDF

## SWAMI VIVEKANAND JUNIOR COLLEGE, Chembur **Ist SEMESTER EXAMINATION 2023-24** **PHYSICS** **Date:** 30/10/2023 **Std.:** FYJC (Sci.) **Marks:** 50 **Time:** 2½ Hrs. **General Instructions:** The question paper is divided into four sections: 1. **SECTION A** - Q. No. 1 contains 7 MCQ carry...

## SWAMI VIVEKANAND JUNIOR COLLEGE, Chembur **Ist SEMESTER EXAMINATION 2023-24** **PHYSICS** **Date:** 30/10/2023 **Std.:** FYJC (Sci.) **Marks:** 50 **Time:** 2½ Hrs. **General Instructions:** The question paper is divided into four sections: 1. **SECTION A** - Q. No. 1 contains 7 MCQ carrying one mark each - Q. No. 2 contains 7 very short answer questions 1 mark each - Q.No. 3 to Q.No.13 contain eleven short answer type questions carrying two marks each. (Attempt any eight) 2. **SECTION B** - Q.No.14 to Q.No.19 contain six short answer type questions, carrying three marks each. (Attempt any four) 3. **SECTION C** - Q.No.20 to Q.No.22 carry four long answer type questions carrying four marks each. (Attempt any two) 4. **SECTION D** - Use of Log table is allowed. - Figures to the right indicate full marks. - For each MCQ it is mandatory to write the correct answer along with it's alphabet. - **PHYSICAL CONSTANTS:** - $\frac{1}{4\pi \epsilon_o} = 9.0 \times 10^9 N m^2 C^{-2}$ - $le = 1.6 \times 10^{-19}$ C ## **SECTION -A** **Q1. Select and write the correct answer** i) Which of the following is not a fundamental unit? - a. cm - b. kg - c. centigrade - d. volt ii) The magnitude of a vector product of a two unit vector making an angle 60 degree with each other is - a. 1 - b. 2 - c. 3/2 - d. √3/2 iii) Which of the following is an ohmic conductor? - a. Transistor - b. Vacuum tube - c. Electrolyte - d. Nichrome wire iv) Changing dimension is known as - a. deformation - b. formation - c. Contraction - d. strain v) An electron placed between two parallel plates connected to a battery. If the battery is switch on the electron will - a. Be attracted to the positive plate - b. Be attracted to the negative plate - c. Remain stationary - d. Will move parallel to the plates vi) The number of significant figures in 0.05718 is - a. 1 - b. 3 - c. 4 - d. 6 vii) The internal resistance of a cell of EMF two 2 Volt is 0.1Ω it is connected to a resistance of 0.9 Ω. The voltage across cell will be - a. 0.5 V - b. 1.8 V - c. 1.95V - d. 3V ## **Q.2 Answer the following:** i) Is it correct to add two vectors representing physical quantities having different dimensions? ii) Define resultant vector. iii) State SI unit of electrical conductivity of a material. iv) The dimensions of stress are v) Charge on an electron is 1.6 X 10^-19C; How many electrons are required to accumulate a charge of one C? vi) A flashlight uses two 1.5 V batteries to provide a steady current of 0.5 A in the filament. Determine the resistance of a glowing filament. vii) State hooke's law. ## **Section - B** Attempt **any Eight**. 16 marks. **Q.3** Define dimensions of a physical quantity. Give two examples. **Q.4** With suitable diagram state the parallelogram law of vectors. **Q.5** How can the voltage rating and current rating of a battery be increased? **Q. 6** Define - i) Tensile stress - ii) Volume strain **Q.7** What is the stress in a wire which is 50 m long and 0.01 cm² in cross section, if the wire bears a load of 100 kg? **Q. 8** State four characteristics of electric lines of force. **Q. 9** Calculate the electric field due to charge of -8.0 X 10^-6Cat a distance of 5.0 cm from it. **Q.10** What is meant by the order of magnitude of a physical quantity? Give two examples. **Q.11** If V₁ = 3 + 4j+kand V₂=i-j+k, determine the magnitude of V₁+ V₂ **Q. 12** Find the colour code for the following value of resistor having tolerance ± 10% - i) 330 Ω - ii) 1 ΚΩ **Q. 13** A Copper wire of radius 0.6mm carries a current of 1A. Assuming the current to be uniformly distributed over a cross - sectional area, find the magnitude of current density ## **Section - C** Attempt **any Four:** (12 Marks). **Q.14** Using dimensional analysis, check whether the physical equation T = $2\pi\sqrt{\frac{l}{g}}$ is dimensionally correct or not. **Q. 15** State coulomb's law and express it in vector form. **Q.16** Using the triangle of vector addition, show that vector addition is associative. **Q. 17** V=at + $\frac{b}{t+c}$ + V_o is a dimensionally valid equation. Obtain the dimensional formula for a, b, and c where V is velocity T is time and V_ois initial velocity. **Q.18** Show that a = 2i +5j-6k and b = i + 5/2j-3k are parallel. **Q. 19** - i) Three resistor 10Ω, 20Ω, & 30Ω are connected in series combination Find equivalent resistance of series combination. - ii) When this series combination is connected to 12 V supply, by neglecting the value of internal resistance, obtain the potential difference across each resistor. ## **Section - D** Attempt **Any TWO**. (8 Mark) **Q.20**Define absolute error and percentage error. In Ohm's experiment, the value of the unknown resistances were found to be 6.12Ω, 6.09Ω, 6.22Ω, 6.15Ω calculate the absolute error and relative error in these measurement. **Q.21** Define the scalar product of two vectors. State two characteristics of scalar product. Given V₁=5i+2j and V₂=ai+6j are perpendicular to each other, determine the value of a. **Q. 22** State and prove Gauss' Theorem in electrostatics. **Q. 23** Define EMF of a cell. State SI unit of EMF. A battery of EMF 12 V an internal resistance 3 Ω Is connected to a resistor. If the current in the circuit is 0.5A, - a) Calculate resistance of resistor - b) Calculate terminal voltage of the battery when the circuit is closed.