Frequency of electric current in alternating current I $=200 \sin \left(60 \pi t+\frac{\pi}{6}\right)$ is :
- A120 Hz
- B60 Hz
- C90 Hz
- ✓30 Hz
Answer: D.
View full solution →Question types
Alternating Current question types
114 questions across 7 question groups — pick any mix to generate a Physics paper with step-by-step answer keys.
114
Questions
7
Question groups
5
Question types
01
M.C.Q (1 Marks)
29 Q→021 Marks Question
41 Q→032 Marks Questions
3 Q→043 Marks Question
13 Q→055 Marks Questions
17 Q→06Case study (4 Marks)
1 Q→07Fill in the blanks.
10 Q→Sample Questions
Alternating Current questions
One sample from each question group in this chapter. Select any group above to see the full set with answer keys.
The number of turns in primary and secondary coils of a transformer are 100 and 300 respectively. If in- put power is 60 W, then output power will be:
- ✓60 W
- B20 W
- C180 W
- DNone of these
Answer: A.
View full solution →A transformer increases ac voltage supply from 220 V to 2200 V. If there are 2000 turns in the second- ary coil, then number of turns in the primary coil is:
- A100
- B50
- ✓200
- D30
Answer: C.
View full solution →Which of the following substance is most suitable to make core of transformer?
- ✓Soft iron
- BNickel
- CCopper
- DStainless steel
Answer: A.
View full solution →Potential difference in ac circuit is $V =20 \sin \omega t$ and current flowing is $I =5 \cos \omega t$, then power dissipated in watts is :
- ✓0
- B10
- C5
- D100
Answer: A.
View full solution →Write the magnitude of average value of alternating current for a complete cycle.
Applied voltage in any ac circuit is 220 V . If $R =8 \Omega, X _{ L }= X _{ C }=6 \Omega$, then find the value of the following :(a) root mean square value of the voltage,
(b) impedance of the circuit.
View full solution →(b) impedance of the circuit.
Write the definition of root mean square value of alternating current.
Calculate power loss in an ac circuit in which magnitudes of voltage and current are as follows :$V =3000 \sin \left(\omega t+\frac{\pi}{2}\right)$ and $I =5 \sin \omega t$
View full solution →If primary coil of a transformer is joined with a battery, then what will happen?
Sunita and her friends went to an exhibition. The guard standing there asked them to pass through a metal detector. Sunita's friends were first afraid but when Sunita told them the reason and explain its working.
Answer the following questions :
(a) State the principle on which metal detector works.
(b) If a person passing through metal detector has some metallic object then why does it produces sound?
(c) Tell two qualities of Sunita which she showed while explaining the reason for passing through it.
Answer the following questions :
(a) State the principle on which metal detector works.
(b) If a person passing through metal detector has some metallic object then why does it produces sound?
(c) Tell two qualities of Sunita which she showed while explaining the reason for passing through it.
When a capacitor is joined with a series LR circuit in series, then current flowing through the circuit increases. Explain, why?
Explain the root mean square value of alternating current.
Draw a graph showing change of alternating current with frequency in LCR series resonant circuit and obtain expression for bandwidth.
Why alternating current of 220 V is more dangerous than direct current of 220 V ?
State difference between the working and non-working current.
Write the difference between alternating current and voltage.
Potential at an instant $t$ in an ac circuit is $E=200 \sin 157 t . \cos 157 t$ volts and current is $I=\sin \left(314 t+\frac{\pi}{3}\right) \quad$ Amperes. In this condition calculate :
(a) frequency
(b) root mean square value of voltage
(c) impedance of the circuit
(d) power factor.
View full solution →(a) frequency
(b) root mean square value of voltage
(c) impedance of the circuit
(d) power factor.
(a) Prove that the mean power supplied to the inductor in a complete cycle is zero. (b) If in an LCR alternatin current circuit $R =$ $24 \Omega, X _{ L }=110 \Omega$, and $X _{ C }=110 \Omega$, then find the impednce of the current.
View full solution →(a) Prove that the peak value ( $I_m$ ) of an alternating current is $\sqrt{2}$ times its root mean square ( rms ) value.(b) If alternating current $I=4 sin \omega t$ of and voltage $V =200 \sin (\omega t+\pi / 3)$, calculate the dissipated average power in the circuit.
View full solution →Match the following
(a) Obtain an expression for current flowing through an ideal inductor joined with an ac source of voltage $v=v_0 \sin \omega t$ by using phasor diagram. Draw a graph between (i) voltage applied and (ii) current as a function of (wt.).
(b) Obtain an expression for average power dissipation in any series LCR circuit.
View full solution →(b) Obtain an expression for average power dissipation in any series LCR circuit.
Draw a phasor diagram for series LCR circuit joined with ac voltage source and obtain an expression for impedance of the circuit.
What is power factor? Explain.
Average value of alternating current in one complete cycle is $...............$
View full solution →Average value of alternating current for half cycle is $...............$
View full solution →Frequency of alternating potential $V= 311 \sin 314 t$ is $...............$
View full solution →If $R=8 \Omega$ and $L=6 \Omega$ are in series, then impedance of the circuit is $...............$
View full solution →Root mean square value of $\text{emf}$ in any $AC$ source is $200 V$. The peak value of voltage is $...............V$
View full solution →Generate a Alternating Current paper free
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