ISC class XI sample paper 1

(This paper consist of two parts ,Part 1 (10 marks). This part consists of compulsory short answer questions , Part 2 (40 marks) this part is divided into 3 sections A,B and C students are requested to answer 2 questions out of 3 from section A, & 1 question out of 2 in section B & C. Each question carries 10 marks.) Part I (10 marks) 1. Convert the following octal to hexadecimal o 26 o 44 o 57 o 91 2. Convert the following fractional number to binary 1. 12.3 2. 5.45 3. 14.5 4. 23.7 3. Convert the following hex into decimal 1. 8B 2. BAD 3. ACC 4. BE Part II (40 marks) Section A (20 marks) Question 1 [10] 1. Define BUS and its types? [2] 2. Differentiate between the following [4] 1. BITS & BYTES 2. SIGN BIT & PARITY BIT 3. Explain exclusive gates XOR & XNOR with truth table and logical circuit. [2] 4. Prove using truth table (4) 1. (A.B)+(A.C)=A.(B+C) 2. A.(A+B)=A Question 2 (10) 1. Explain with logic gate diagram why NAND, NOR gates are called universal gates?(Draw all the six realizations) [5] 2. Explain Full adder circuit with help of logic gate diagram, truth table, equation? [5] Question 3 (10) 1. Explain the working of D flip flop with logic circuit diagram, and truth table? [3] 2. Define what is assembly language? [2] 3. What is instruction cycle? Explain each phase [5] Section B (10 marks) Question 4 (10) 1. Explain the following terms 1. CPU 2. Register addressing 3. UPS 4. CPU Heat sink 5. ALU Question 5 [10] 1. Mention different types Processor available in market 2. Mention one difference each for the following 1. Address & Data Buses 2. CISC & RISC architecture 3. Direct & Indirect addressing modes 3. Explain all the types of memory unit components. [2] [3] [5] Section C (10 marks) Question 6. (10) Write a program to input a number and check if it is a smith number, A smith number is composite number, the sum of whose digits is the sum of the digits of its prime factors (excluding 1) for ex 94 is smith number because sum of prime factors of 94 is 2,47 i.e 2+(4+7)=13 and sum of digits is 9+4=13. Question 7. (10) Eagle travels has given following discount to its customers based on tickets bought. Tickets amount Discount Above 70001 18% 55001 -70000 16% 35001 -55000 12% 25001 – 35000 10% Less than 25000 2% Write a program to input the name & ticket amount from the user, calculate & print the discount amount and net amount to be paid