set-4

151. In a vectored interrupt

1. The branch address is assigned to a fixed location in memory.
2. The interrupting source supplies the branch information to the processor through an interrupt vector.
3. The branch address is obtained from a register in the processor.
4. None of the above.

152. A sequence of two instructions that multiplies the contents of the DE register pair by 2 and stores the result in the HL register pair (in 8085 assembly language) is

1. XCHG and DAD B
2. XTHL and DAD H
3. PCHL and DAD D
4. XCHG and DAD H

153. The most relevant addressing mode to write position-independent code is

1. Direct mode
2. Relative mode
3. Indirect mode
4. Indexed mode

154. Which of the following are CISC machines?

1. IBM 360
2. 68030
3. 80386
4. All of the above

155. The working of a staircase switch is a typical example of the logical operation

1. OR
2. Exclusive-OR
3. NOR
4. Exclusive-NOR

156. Which of the following are typical characteristics of a RISC machine?

1. Instruction taking multiple cycles
2. Multiple register sets
3. Highly pipelined
4. Both 2 and 3

157. A microprogrammed control unit

1. Is faster than a hardwired control unit
2. Facilitates easy implementation of new instructions
3. Is useful when very small programs are to be run
4. Usually refers to the control unit of a microprocessor

158. Parallel printer uses

1. RS-232C interfaces
2. Handshake mode
3. Centronics interface
4. Both 2 and 3

159. The ASCII code 56 represents the character

1. V
2. A
3. 8
4. Carriage return

160. The number of possible Boolean functions that can be defined for n Boolean variables over n-valued Boolean algebra is

1. ( 2^{n^2} )
2. ( 2^{n^2} )
3. ( n^{2^n} )
4. ( n^{n^2} )

161. The advantage of a single bus over a multi-bus is the

1. Low cost
2. Flexibility in attaching peripheral devices
3. Both 1 and 2
4. High operating speed

162. Which of the following rules regarding the addition of 2 given numbers is correct, if negative numbers are represented in 2’s complement form?

1. Add sign bit and discard carry, if any.
2. Add sign bit and add carry, if any.
3. Do not add sign bit and discard carry, if any.
4. Do not add sign bit and add carry, if any.

163. When INTR is encountered, the processor branches to the memory location, which is

1. 0024H
2. Determined by the “call address” instruction issued by the I/O device
3. Determined by the “RST N” instructions issued by the I/O device
4. Both 2 and 3

164. In which of the following instructions does bus idle situation occur?

1. EI
2. INX H
3. DAD rp
4. DAA

165. Any instruction should have at least

1. 2 operands
2. 3 operands
3. 1 operand
4. None of the above

166. If the cache needs an access time of 20ns and the main memory 120 ns, then the average access time of a CPU is (assume hit-ratio is 80%)

1. 30ns
2. 35ns
3. 40ns
4. 45ns

167. The number of clock cycles necessary to complete 1 fetch cycle in 8085 (excluding wait state) is

1. 3 or 4
2. 4 or 6
3. 4 or 5
4. 3 or 5

168. The seek time of a disk is 30ms. It rotates at the rate of 30 rotations per second. Each track has a capacity of 300 words. The access time is approximately

1. 47ms
2. 60ms
3. 50ms
4. 62ms

169. Motorola’s 68040 is comparable to

1. 8085
2. 80386
3. 80286
4. 80486

170. The possible number of Boolean functions of 3 variables X, Y, and Z such that f(X, Y, Z) = F(X’, Y’, Z’) is

1. 8
2. 64
3. 16
4. 32

171. Which of the following interrupts is both level and edge sensitive?

1. RST 5.5
2. RST 7.5
3. INTR
4. TRAP

172. The difference between 80486 and 80386 is/are

1. Presence of floating-point co-processor
2. Speed of operation
3. Presence of 8 K cache on chip
4. All of the above

173. The addressing mode used in the instruction PUSH B is

1. Direct
2. Register direct
3. Register
4. Immediate

174. Which of the following architecture is/are not suitable for realizing SIMD?

1. Vector processor
2. Von Neumann
3. Array processor
4. All of the above

175. The total number of possible Boolean functions involving ‘n’ Boolean variables is

1. Infinitely many
2. ( n^2 )
3. ( n^n )
4. None of the above

176. If ((11A1B)_8 = (12C9)_16) (C stands for decimal 12), then the value of A and B are:

1. 5,1
2. 5,7
3. 7,5
4. None of the above

177. Which of the following operations(s) is/are not closed as regards to computers?

1. Addition
2. Multiplication
3. Subtraction
4. All of the above

178. Which of the following units can be used to measure the speed of a computer?

1. SYPS
2. FLOPS
3. MIPS
4. Both 2 and 3

179. If A XOR B = C, THEN

1. A XOR B = B
2. A XOR B XOR C = 0
3. B XOR C = A
4. All of the above

180. Addressing capability of 8086/88 are

1. 64 K
2. 2 MB
3. 512 K
4. 1 MB

181. Bubble memories are preferable to floppy disks because

1. Of their higher transfer rate
2. Of their reliability
3. They consume less power
4. Both 2 and 3

182. The XOR operation is

1. Commutative
2. Associative
3. Both 1 and 2
4. Distributive over AND operator

183. Which of the following logic families is well suited for high-speed operation?

1. TTL
2. MOS
3. ECL
4. CMOS

184. Which of the following does not have 8 data lines?

1. 8085
2. 8088
3. 8086
4. Z-80

185. Negative numbers cannot be represented in

1. Signed magnitude form
2. 2’s complement form
3. 1’s complement form
4. None of the above

186. The addressing mode used in an instruction of the form ADD X, Y is

1. Absolute
2. Index
3. Indirect
4. None of the above

187. Which of the following are registers?

1. Accumulator
2. Program counter
3. Stack pointer
4. All of the above

188. IBM developed a bus standard for their line of computers ‘PC AT’ called______.

1. IB bus
2. ISA
3. M-bus
4. None of these

189. Which of the following is the programmable internal timer?

1. 8251
2. 8253
3. 8250
4. 8275

190. Bipolar devices are desirable in the fabrication of which of the following components?

1. Main memory
2. Microprogram memory
3. Cache memory
4. All of the above

191. A+B can be implemented by

1. NAND gates alone
2. NOR gate alone
3. Both 1 and 2
4. None of the above

192. Which of the following are the correct statements?

1. Bus is a group of information-carrying wires
2. Bus is needed to achieve reasonable speed of operation
3. Bus can carry data or address lines, a bus can be shared by more than one device
4. All of the above

193. A number system uses 20 as the radix. The excess code that is necessary for its equivalent binary-coded representation is

1. 4
2. 6
3. 5
4. 7

194. Any given truth table can be represented by a

1. Karnaugh map
2. Sum of product of Boolean expressions
3. Product of sum of Boolean expressions
4. All of the above

195. Which of the following remarks about PLA is/are true?

1. It produces product of sum as the output
2. It produces sum of products as the output
3. It is general
4. Both 2 and 3

196. The first operating system used in microprocessor is

1. Zenix
2. CP/M
3. DOS
4. Multics

197. Which of the following does not need extra hardware for DRAM refreshing?

1. 8085
2. Z-80
3. Motorola-6800
4. None of the above

198. The advantage of MOS devices over bipolar devices is

1. It allows higher bit densities and also cost-effective
2. It is easy to fabricate
3. Its higher impedance
4. All of the above

199. Which of the following comments about the Program Counter (PC) are true?

1. It is a register
2. It is a cell in ROM
3. During execution of the current instruction, its content changes
4. Both 1 and 3

200. Choose the correct statements from the following

1. By scanning a bit pattern, one can say whether it represents data or form
2. Whether a given piece of information is data or not depends on the particular applications
3. Positive number cannot be represented in 1’s complement form
4. Both 2 and 3