Difference Between EMF and Voltage MCQs

Content Curator

The difference between EMF and voltage is that the EMF is the potential difference measured across a power source without a load connected to it whereas voltage is the potential difference measured between any two points in a circuit. The article covers important MCQs on the Difference Between EMF and Voltage.

Difference Between EMF and Voltage

Difference Between EMF and Voltage

Ques 1: For accurate measurements, the resistance of a voltmeter should be

infinite
as small as possible
as large a possible
equal to the resistance across which potential difference is to be measured

Click here for the answer

Answer: The correct answer is (c) as large as possible

Explanation: Voltmeter when connected across any circuit element should not draw any current from it. If the voltmeter resistance is not high as compared to the resistance of the circuit element, across which it is connected, the measured voltage becomes less. Thus the resistance of the voltmeter should be as large as possible.

Ques 2: If a wire of resistance 2Ω is covered with ice and a voltage of 210V is applied across the wire, then the rate of melting ice would be

0.85g/s
1.92g/s
6.56g/s
none of the above

Click here for the answer

Answer: The correct answer is (c) 5.56g/s

Explanation: The rate at which heat is produced in the wire is heat/time = V²/R = 2205Js⁻¹

Latent heat of ice = 80c/gm = 80x4.2J/gm

Hence rate of melting ice would be = 2205/80X4.2 = 6.56g/s

Ques 3: If the ammeter shows a reading of 10A and the voltmeter having internal resistance of 3000 Ω measures a voltage of 200V, the resistance R is given by

201.3 Ω
2013 Ω
20.13 Ω
20.00 Ω

Click here for the answer

Answer: The correct answer is (c) 20.13 Ω

Explanation: Applying Ohm’s law in section PQ

V=IR

The resistances, R and internal resistance of the voltmeter are connected in parallel

I/V = 1/R + 1/R_v

1/R = I/V − 1/R_v

Thus, R = V/I−V/R_v

putting the respective values and calculating we find R=20.13Ω

Ques 4: Two battery having unequal emf

cannot be connected in parallel.
cannot be connected in series.
both a and d
can be connected in series only

Click here for the answer

Answer: The correct answer is (c) both a and d

Explanation: We cannot connect the two batteries in parallel, when they have unequal voltage. If we connect them in parallel, then the low voltage battery will be charged by the high voltage battery. So, there is a chance of causing damage to the circuit. But, if we connect them in series, then both voltages are added together and we get that added voltage at output side. Hence, two batteries having unequal voltage can be connected in series only.

Ques 5: When the battery is being charged, the terminal voltage decreases with

increasing charging rate
increasing temperature
increasing state of charge
none of these

Click here for the answer

Answer: The correct answer is (b) increasing temperature

Explanation: Whenever a battery is being charged, the terminal voltage of the battery changes a small amount whenever the battery temperature changes. As the battery temperature increases, its terminal voltage decreases or as the terminal voltage decreases, its temperature increases. This is usually called as temperature compensation in a storage battery.

Chapter Related Topics
Meter Bridge	Potentiometer	Combination of Resistors
Cells, emf, Internal Resistance	Static Electricity	Resistor Color Codes
Combination of Resistors-Series and Parallel	Electrical Current	Resistor Colour Codes
Unit of Voltage	Electrical Resistance	Types of Resistors
Unit of Specific Resistance	Carbon Resistor	Types of Current
Uses of Resistor	Derivation of Drift Velocity	Resistivity Temperature Dependence
Power Of Alternating Current	Difference between AC and DC	Permittivity And Permeability

Ques 6: The induced voltage will oppose the flux producing it. State True/False.

True
False

Click here for the answer

Answer: The correct answer is (a) True

Explanation: According to Lenz law, the induced voltage acts in such a way that it opposes the flux producing it. This is indicated by a negative sign.

Ques 7: Calculate the emf when a coil of 100 turns is subjected to a flux rate of 0.3 tesla/sec.

3
30
-30
-300

Click here for the answer

Answer: The correct answer is (c) -30

Explanation: The induced emf is given by Vemf = -dλ/dt = -Ndψ/dt. Thus emf will be -100 x 0.3 = -30 units.

Ques 8: According to Faraday’s law, EMF stands for

Electromagnetic field
Electromagnetic force
Electromagnetic friction
Electromotive force

Click here for the answer

Answer: The correct answer is (d) Electromotive force

Explanation: The force in any closed circuit due to the change in the flux linkage of the circuit is called as electromotive force EMF. This phenomenon is called as Faraday’s law.

Ques 9: Calculate the emf when the flux is given by 3sin t + 5cos t

3cos t – 5sin t
-3cos t + 5sin t
-3sin t – 5cos t
3cos t + 5sin t

Click here for the answer

Answer: The correct answer is (b) -3cos t + 5sin t

Explanation: The electromotive force is given by Vemf = -dλ/dt. Thus Vemf = -dλ/dt = -(3cos t – 5sin t) = -3cos t + 5sin t.

Ques 10: Two parallel plates are separated by a distance D charged by V volt. The field intensity E is given by,

V × D
V / D
V × D²
V² / D

Click here for the answer

Answer: The correct answer is (b) V / D

Explanation: Electric field intensity between two points is always expressed as the potential difference between these two points divided by the distance between them. The strength of electric field or electric field intensity is measured by volt per meter or newton per meter.

Do Check Out:

Study Guides
NCERT Solutions for Class 12 Physics	Class 12 Physics Notes	Formulas in Physics
Topics for Comparison in Physics	Choice-based questions in physics	Topics with relation in physics
Physics Study Notes	Class 12 Physics Book PDF	Class 12 Physics Practicals
Important Derivations in Physics	SI units in Physics	Important Physics Constants and Units
Class 12 Physics Syllabus	NCERT Solutions for Class 12 Chemistry	NCERT Solutions for Class 12 Biology
NCERT Solutions for Class 12 English	NCERT Solutions for Class 12 Maths	Class 12 Chemistry Practicals
Class 12 Chemistry Notes	Class 12 Biology Notes	Class 12 Maths Notes
Class 12 PCMB Notes	NCERT Class 12 Biology Book	NCERT Class 12 Maths Book
NCERT Class 12 Textbooks	NCERT Solutions for Class 11 Maths	NCERT Solutions for Class 11 Physics
NCERT Solutions for Class 11 Chemistry	NCERT Solutions for Class 11 Biology	NCERT Solutions for Class 11 English
NCERT Class 11 Chemistry Book	NCERT Class 11 Physics Book	NCERT Class 11 Biology Book
Class 11 Notes	Important Maths Formulas	Important Chemistry Formulas
Class 11 PCMB Syllabus	Chemistry Study Notes	Biology Study Notes
Periodic Table in Chemistry	Important Chemical Reactions	Comparison topics in Chemistry
Comparison Topics in Maths	Comparison Topics in Biology	Important Named Reactions
Maths MCQs	Biology MCQs	Chemistry MCQs

Difference Between EMF and Voltage MCQs

CBSE CLASS XII Related Questions

1.
Photoemission of electrons occurs from a metal (\( \phi_0 = 1.96 \, \text{eV} \)) when light of frequency \( 6.4 \times 10^{14} \, \text{Hz} \) is incident on it. Calculate: Energy of a photon in the incident light, The maximum kinetic energy of the emitted electrons, and The stopping potential.

3.
Draw a circuit diagram of a full-wave rectifier using p-n junction diodes. Explain its working and show the input-output waveforms.

5.
If both the number of protons and the neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice versa) in a nuclear reaction? Explain.

6.
The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be:

Comments

SUBSCRIBE TO OUR NEWS LETTER

Difference Between EMF and Voltage MCQs

CBSE CLASS XII Related Questions

1.Photoemission of electrons occurs from a metal (\( \phi_0 = 1.96 \, \text{eV} \)) when light of frequency \( 6.4 \times 10^{14} \, \text{Hz} \) is incident on it. Calculate: Energy of a photon in the incident light, The maximum kinetic energy of the emitted electrons, and The stopping potential.

3.Draw a circuit diagram of a full-wave rectifier using p-n junction diodes. Explain its working and show the input-output waveforms.

5. If both the number of protons and the neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice versa) in a nuclear reaction? Explain.

6.The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be:

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
Photoemission of electrons occurs from a metal (\( \phi_0 = 1.96 \, \text{eV} \)) when light of frequency \( 6.4 \times 10^{14} \, \text{Hz} \) is incident on it. Calculate: Energy of a photon in the incident light, The maximum kinetic energy of the emitted electrons, and The stopping potential.

3.
Draw a circuit diagram of a full-wave rectifier using p-n junction diodes. Explain its working and show the input-output waveforms.

5.
If both the number of protons and the neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice versa) in a nuclear reaction? Explain.

6.
The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be: