Microcontroller set 15

Que: 141. DS1307 control register has an address of
a. 00H
b. 03H
c. 07H
d. 10H
Que: 142. What does the CH bit of the DS1307 demonstrate?
a. clock high
b. clock halt
c. clear high
d. clear halt
Que: 143. Why are relays used for driving the motors?
a. they act as a switch for driving motors
b. they increase the current capability required by the motors
c. they are used to reduce the back emf from the motors
d. all of the mentioned
Que: 144. Why are ULN2803 normally used between the micro controllers and the relays?
a. for switching purposes
b. for increasing the current capability required by a relay
c. for increasing the voltage capability required by a relay
d. all of the mentioned
Que: 145. Why are opto isolators normally used between the micro controllers and the ULN2803?
a. to optimise the current
b. to reduce the back emf
c. to increase the current
d. to increase the voltage
Que: 146. Which of the following is a type of a electromagnetic relay?
a. SPST
b. SPDT
c. DPDT
d. All of the mentioned
Que: 147. Reed switches show connectivity whenever they are in the presence of an electrical field?
a. TRUE
b. FALSE
c. can’t say
d. depends on the conditions
Que: 148. Which of the following is an application of stepper motors?
a. in printers
b. in robots
c. in vehicles
d. all of the mentioned
Que: 149. What are normal 4 step sequence of a stepper motor if we start to move in clockwise direction with 0110 value?
a. 1100100100110110
b. 11100111000110
c. 1001110001100010
d. 101101001011010
Que: 150. What is the meaning of a step angle?
a. angle which a stepper motor has
b. angle between the two windings of the stator in a stepper motor
c. minimum degree of rotation associated with a step angle
d. angle between the stator and the rotor