Home
FREE Trial
Login
Search Result
26
Record(s) found!
JEE-Main - Grade 12 - Physics - Alternating Current - Introduction and Snapshot of Alternating Current - Study ref# 824
Introduction: We have so far considered direct current (dc) sources and circuits with dc sources. These currents do not change direction with time. But voltages and currents that vary with time are very common. The electric mains suppl...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Introduction and Snapshot of Alternating Current - Study ref# 825
Following section must be covered to understand the Alternating Current: 1. Introduction 2. AC Voltage Applied to a Resistor 3. Representation of AC Current and Voltage by Rotating Vectors – Phasors 4. AC Voltage Applied to an In...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Target Setup for Alternating Current - Study ref# 826
Student requires to achieve the following milestones to get better grip over Alternating Current. The milestones / targets are as follows: Starting Point: Days 0Test TypeAppear on TestTarget TestsScorePractice Test000%Chapter Tes...
read more
JEE-Main - Grade 12 - Chemistry - Electrochemistry - Study ref# 9742
Why is alternating current used for measuring resistance oof an electrolytic solution? Answer: Alternating current is used in electrolysis so that concentration of ions in the solution remains constant and extract value of resistance is m...
read more
JEE-Main - Grade 12 - Physics - Electromagnetic Induction - Study ref# 10544
A cylindrical bar magnet is rotated about its axis in the figure. A wire is connected from the axis and is made to touch the cylindrical surface through a contact. Then (a) a direct current flows in the ammeter A. (b) no current fl...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10562
An alternating current generator has an internal resistance Rg and an internal reactance Xg.It is used to supply power to a passive load consisting of a resistance Rg and a reactance XL.For maximum power to be delivered from the generato...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10563
When a voltage measuring device is connected to AC mains, the meter shows the steady input voltage of 220V. this means (a) Input voltage cannot be AC voltage, but a DC voltage. (b) Maximum input voltage is 220V. (c) The meter reads ...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10564
To reduce the resonant frequency in an L-C-R series circuit with a generator (a) the generator frequency should be reduced. (b) another capacitor should be added in parallel to the first. (c) the iron core of the inductor should ...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10565
Define capacitive reactance. Write its S.I. unit. Answer: It is defined as the opposition to the flow of current in ac circuits offered by a capacitor. Alternatively,
S.I. unit: oh...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10566
State which of the two a capacitor or an inductor, tends to become SHORT when the frequency of the applied alternating voltage has a high value. Answer: The capacitor. Detailed Answer: Between inductor and capacitor, the capacitor w...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10567
The figure shows sinusoidal curves representing oscillating supply voltage and current in an ac circuit. Draw a phasor diagram to represent the current and supply voltage appropriately as phasors. State the phase difference between th...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10568
A lamp is connected in series with a capacitor. Predict your observation for dc and ac connections. What happens in each if the capacitance of the capacitor is reduced? Answer: When a dc source is connected to a capacitor, the capacitor gets...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10569
Show that in the free oscillations of an LC circuit, the sum of energies stored in the capacitor and the inductor is constant in time. Answer: At an instant t, charge q on the capacitor and the current i are given by:
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10570
Which of the following combinations should be selected for better tuning of an L-C-R circuit based for communication? (a)
(b)
(c...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10571
Define ‘Wattless current’. Answer: Current flowing in a circuit without any net dissipation of power, is called wattless current....
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10572
An alternating voltage is applied to the circuit containing a resistor R connected in series with a black box. The current in the circuit is found to be
(i) State whether the element ...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10573
A capacitor ‘C’, a variable resistor ‘R’ and a bulb ‘B’ are connected in series to the ac mains in circuit as shown. The bulb glows with some brightness. How will the glow of the bulb change if (i) a dielectric slab is introduced between the...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10574
A source of ac voltage, is connected across a pure inductor of inductance L. Derive the expressions for the instantaneous current in the circuit. Show that average power dissipated in the circuit is zero. Answer: Derivation of instantaneous...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10575
A sinusoidal voltage of peak 10 V is applied to a series LCR circuit in which resistance, capacitance and inductance have values of 10, 1and 1 H respectively. Find (i) the peak voltage across the inductor at resonance (ii) quality fact...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10576
(i) When ac source is connected to an ideal inductor shows that the average power supplied by the source over a complete cycle is zero. (ii) A lamp is connected in series with an inductor and an ac source. What happens to the brightness o...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10577
An inductor L of inductance XL is connected in series with a bulb B and an ac source. How would brightness of the bulb change when (i) number of turns in the inductor is reduced, (ii) an iron rod is inserted in the inductor and (iii) a capac...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10578
A circuit containing an 80mH inductor and a 250capacitor in series connected to a 240 V, 100rad/s supply. The resistance of the circuit is negligible. (i) obtain rms value of current. (ii) What is the total average power consumed by...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10579
An inductor of reactance 1and a resistor of 2 are connected in series to the terminals of a 6V(rms) ac source. The power dissipated in the circuit is (a) 8W (b) 12W (c) 14.4W (d) 18W Answer: Correct option: (c) Here,
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10580
Why is the core of a transformer laminated? Answer: To reduce the iron loss, the iron core of a transformer is laminated. Detailed Answer: The main purpose of transformer core is to transfer the flux from primary winding to secondar...
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10581
The output of a step-down transformer is measured to be 24V when connected to a 12 W light bulb. The value of the peak current is (a)
(b)
read more
JEE-Main - Grade 12 - Physics - Alternating Current - Study ref# 10582
Show a plot of variation of alternating emf versus time generated by a loop of wire rotating in a magnetic field. Answer: ...
read more
Search
Check your desired chapters availability
Select Course
JEE Main
NEET
Type your query
Search
Sample Test
New Student? Sign Up
Log In