ICM 7217, ICL7107 and ULN2803 multiple choice questions

ICM 7217

Which among the following controls the frequency of onboard multiplex oscillator in 4-digit ICM 7217A LED display?
a) Resistor
b) Digit Driver
c) Capacitor
d) Segment Decoder
Answer: Capacitor

ICL7107

Which phase of 31/2 digit LED Panel meter (7107/7106) to the process of conversion reveals the averaging of signal input for about 1000 clock pulses?
a) Auto-zero phase
b) Signal Integrate Phase
c) Reference Integrate Phase
d) All of the above
Answer: Signal Integrate Phase

ULN2803

Why do we need a ULN2803 in driving a relay?
a) for switching a motor
b) for increasing the current limit in the relays
c) for increasing the power
d) for decreasing the current limit in the relays
Answer: for increasing the current limit in the relays