KCET SERIES Physics
Alternating Current
28 previous year questions.
Volume: 28 Ques
Yield: High
High-Yield Trend
3
2026 1
2025 1
2022 1
2020 1
2019 5
2018 1
2017 3
2016 3
2015 3
2013 2
2011 1
2009 2
2008 1
2003 Chapter Questions 28 MCQs
01
PYQ 2003
easy
physics ID: kcet-200
The time taken by AC of 50 Hz in reacting from zero to the maximum value is
1
2
3
4
02
PYQ 2008
medium
physics ID: kcet-200
The value of alternating emf in the given circuit will be
1
220 V
2
140 V
3
100 V
4
20 V
03
PYQ 2008
medium
physics ID: kcet-200
A current of is flowing at in the primary coil of a transformer. If the voltage produced in the secondary coil is and of power is lost, then the current in the secondary will be
1
2.5 A
2
5 A
3
0.25 A
4
0.5 A
04
PYQ 2009
easy
physics ID: kcet-200
An electric heater rated and is connected to mains. The current drawn by it is
1
2.5 A
2
0.4 A
3
1.25 A
4
0.8 A
05
PYQ 2011
medium
physics ID: kcet-201
A transformer works on the principle of
1
self induction
2
electrical inertia
3
mutual induction
4
magnetic effect of the electrical current
06
PYQ 2011
medium
physics ID: kcet-201
In an A.C. circuit, V and I are given by V=150 sin(150 t) volt and I=150 A. The power dissipated in the circuit is
1
106 W
2
150 W
3
5625 W
4
zero
07
PYQ 2013
medium
physics ID: kcet-201
In series circuit, the potential differences across each element is . Now the value of the resistance alone is doubled, then across and respectively
1
20 V, 10 V, 10 V
2
20 V, 20 V, 20 V
3
20 V, 40 V, 40 V
4
10 V, 20 V, 20 V
08
PYQ 2013
medium
physics ID: kcet-201
For a transformer, the turns ratio is and its efficiency is . The current flowing in the primary coil is and the voltage applied to it is . Then the voltage and the current flowing in the secondary coil are _________ respectively.
1
150 V, 1.5 A
2
300 V, 0.5 A
3
300 V, 1.5 A
4
150 V, 0.5 A
09
PYQ 2013
medium
physics ID: kcet-201
A series combination of resistor and capacitor is connected to an source of angular frequency . Keeping the voltage same, if the frequency is changed to , the current becomes half of the original current. Then the ratio of the capacitive reactance and resistance at the former frequency is
1
2
3
4
10
PYQ 2015
medium
physics ID: kcet-201
The average power dissipated in a pure inductor is
1
2
3
zero
4
11
PYQ 2015
medium
physics ID: kcet-201
A transformer is used to light lamp from mains. If the main current is , the efficiency of the transformer is
1
0.9
2
0.95
3
0.96
4
0.99
12
PYQ 2015
medium
physics ID: kcet-201
In an circuit, at resonance
1
the current and voltage are in phase
2
the impedance is maximum
3
the current is minimum
4
the current leads the voltage by
13
PYQ 2016
medium
physics ID: kcet-201
The value of current in a circuit is . The average value of current over a cycle is
1
2
3
Zero
4
14
PYQ 2016
medium
physics ID: kcet-201
In a series circuit an alternating and current are given by the equation The average power dissipated in the circuit over a cycle of is
1
2
3
4
Zero
15
PYQ 2016
medium
physics ID: kcet-201
A capacitor of capacitance is connected to an source and an Ammeter. If the source voltage varies as , the reading of the ammeter is
1
50 mA
2
70.7 mA
3
5.0 mA
4
7.07 mA
16
PYQ 2017
medium
physics ID: kcet-201
A coil of inductive reactance and resistance is connected to a , supply. The time lag between maximum voltage and current is
1
2
3
4
17
PYQ 2018
easy
physics ID: kcet-201
Which of the following, represents the variation of inductive reactance with the frequency of voltage source (v) ?
1
2
3
4
18
PYQ 2018
medium
physics ID: kcet-201
In Karnataka, the normal domestic power supply AC is 220 V, 50 Hz. Here 220 V and 50 Hz refer to
1
Peak value of voltage and frequency
2
rm s value of voltage and frequency
3
Mean value of voltage and frequency
4
Peak value of voltage and angular frequency
19
PYQ 2018
medium
physics ID: kcet-201
A 100 W bulb is connected to an AC source of 220 V, 50 Hz. Then the current flowing through the bulb is
1
2
3
4
20
PYQ 2018
easy
physics ID: kcet-201
In the series LCR circuit, the power dissipation is through
1
R
2
L
3
C
4
Both L and C
21
PYQ 2018
medium
physics ID: kcet-201
A step-up transformer operates on a 230 V line and a load current of 2 A. The ratio of primary and secondary windings is 1 : 25. Then the current in the primary is
1
25 A
2
50 A
3
100 A
4
12.5 A
22
PYQ 2019
medium
physics ID: kcet-201
The frequency of an alternating current is 50 Hz. What is the minimum time taken by current to reach its peak value from rms value?
1
2
s
3
s
4
s
23
PYQ 2020
medium
physics ID: kcet-202
A 220 V A.C supply is connected between points A and B as shown in figure what will be the potential difference V across the capacitor?
1
220 V
2
110 V
3
0
4
24
PYQ 2022
medium
physics ID: kcet-202
If a voltage across a bulb rated 220 V, 100 W drops by 2.5 % of rated value. the percentage of rated value by which the power would decrease is
1
5%
2
20%
3
10%
4
2.5%
25
PYQ 2025
medium
physics ID: kcet-202
In domestic electric mains supply, the voltage and the current are
1
DC voltage and AC current
2
AC voltage and AC current
3
AC voltage and DC current
4
DC voltage and DC current
26
PYQ 2026
medium
physics ID: kcet-202
A small town with a demand of 900 kW of electric power at 220 V is situated 20 km away from an electric power generating station. The two-wires line has resistance per unit length of . The town gets power from the line through 45000 V to 220 V stepdown transformer at a substation in the town. The line power loss in the form of heat is
1
4 kW
2
8 kW
3
40 kW
4
80 kW
27
PYQ 2026
medium
physics ID: kcet-202
In a circuit containing a pure resistor connected to an AC source,
1
Voltage leads the current by 90
2
Current leads the voltage by 90
3
Voltage and current are in same phase with each other
4
Current leads the voltage by 180
28
PYQ 2026
medium
physics ID: kcet-202
A light bulb rated 100 W is connected to an AC source of 220 V, 50 Hz. The rms current through the bulb is
1
0.454 A
2
0.545 A
3
2.20 A
4
0.22 A
About Alternating Current - KCET
Alternating Current is a vital chapter for KCET aspirants. Mastering the concepts covered in this chapter is essential for securing a top rank.
By rigorously practicing the previous year questions associated with this chapter, you can identify high-yield topics, understand the examiner's perspective, and boost your confidence during the actual exam.
Frequently Asked Questions
Why focus on Alternating Current PYQs?
Analyzing PYQs for this specific chapter reveals the most frequently tested concepts and the typical complexity of questions, allowing you to tailor your study plan efficiently.
How to best use this analysis?
Review the topic breakdown to see which sub-topics within Alternating Current carry the most weight. Then, tackle the questions iteratively to solidify your understanding.