# Electrical Measurements Questions and Answers – Delay Line

This set of Electrical Measurements & Measuring Instruments Multiple Choice Questions & Answers (MCQs) focuses on “Delay Line”.

1. CRO uses __________
a) 2 delay lines
b) 3 delay lines
c) 4 delay lines
d) 5 delay lines

Explanation: Cathode Ray Oscilloscope uses two delay lines. They are as follows:
Lumped parameter delay line and
Distributed parameter delay line.

2. T section in a delay circuit of CRO acts as ________
a) high pass filter
b) low pass filter
c) band pass filter
d) band reject filter

Explanation: In the delay circuit of a CRO, T section is present in the lumped parameter delay line. The T section acts as a low pass filter having a cut off frequency as,
.

3. Lumped parameter delay line consists of________
a) RC networks
b) RL networks
c) LC networks
d) Resistive networks

Explanation: In the delay line circuit of a Cathode Ray Oscilloscope, the lumped parameter delay line is made of several cascaded LC networks. They are known as T sections.

4. Delay for the T section is given by ________
a) ts = 1fc
b) ts = 1
c) ts = 1π
d) ts = 1πfc

Explanation: In the T section of the lumped parameter delay in a delay line circuit of the CRO the delay is given by the relation
ts = 1πfc
ts = delay for a single circuit
td = total delay
n = number of T sections.

5. Distributed parameter delay line is a transmission line.
a) True
b) False

Explanation: The delay line circuit consists of distributed parameter delay as well as lumped parameter delay. The distributed parameter delay is basically a transmission line with a coil wound on a helix mandrel.

6. Inductance does not affect a transmission line.
a) True
b) False

Explanation: The inductance of the transmission line in a distributed parameter delay line can be increased by winding the inner conductor of the helix onto a ferromagnetic core.

7. Typical values for a distributed parameter delay line are ________
a) Zo = 10 Mῼ and td = 10 nsec/m
b) Zo = 1 kῼ and td = 500 nsec/m
c) Zo = 1000 ῼ and td = 180 nsec/m
d) Zo = 100 Gῼ and td = 275 nsec/m

Explanation: For the distributed parameter delay line in a delay line circuit the typical parameters are the characteristic impedance which is Zo = 1000 ῼ and the delay time which is td = 180 nsec/m.

8. What is the effect of the signal delay on the sweep generator?
a) no effect
b) input increases in magnitude
c) output doesn’t get any delay
d) output gets sufficient delay

Explanation: When the signal is delayed, the sweep generator’s output gets sufficient time in order to reach the horizontal plates before the signal passes over to the vertical deflection plates.

Sanfoundry Global Education & Learning Series – Electrical Measurements.