The variation of EMF with time for four types of generators is shown in the figures. Which amongst them can be called AC voltage?

   
(a) (b)
   
(c) (d)

Choose the correct option from the given ones:

1. (a) and (d)
2. (a), (b), (c), and (d)
3. (a) and (b)
4.  only (a)

Subtopic:  AC vs DC |
 79%
Level 2: 60%+
NEET - 2019
Hints
Links

An AC ammeter is used to measure the current in a circuit. When a given direct current passes through the circuit, the AC ammeter reads \(6~\text A.\) When another alternating current passes through the circuit, the AC ammeter reads \(8~\text A.\) Then the reading of this ammeter if DC and AC flow through the circuit simultaneously is:
1. \(10 \sqrt{2}~\text A\) 
2. \(14~\text A\) 
3. \(10~\text A\) 
4. \(15~\text A\) 

Subtopic:  AC vs DC |
 67%
Level 2: 60%+
Hints
Links

In the diagram, two sinusoidal voltages of the same frequency are shown. What is the frequency and the phase relationship between the voltages?
        

Frequency in Hz Phase lead of \(N\) over \(M\) in radians
1. \(0.4\) \(-\pi/4\)
2. \(2.5\) \(-\pi/2\)
3. \(2.5\) \(+\pi/2\)
4. \(2.5\) \(-\pi/4\)
Subtopic:  AC vs DC |
 68%
Level 2: 60%+
Hints
Links

advertisementadvertisement

A direct current of \(5~ A\) is superimposed on an alternating current \(I=10sin ~\omega t\) flowing through a wire. The effective value of the resulting current will be:

1. \(15/2~A\) 2. \(5 \sqrt{3}~A\)
3. \(5 \sqrt{5}~A\) 4. \(15~A\)
Subtopic:  AC vs DC |
 61%
Level 2: 60%+
Hints
Links