Unit of Current MCQs

Content Curator

Unit of Current is Ampere. Ampere is the SI unit of current. It forms one of the fundamental units of physical quantities. Ampere is denoted by A. Electric current is the rate of flow of charge. The value of the charge of an electron e is 1.602 x 176634 ×10^-19. Unit of current is very important to know to solve problems related to Current Electricity.

Check Out:

MCQs and Important Questions from Related Topics
Kirchhoff’s Rules MCQ	Electrical Current MCQ	Cells, emf, Internal Resistance MCQ
Kirchhoff’s Rules QnA	Electrical Current QnA	Cells, emf, Internal Resistance QnA
Ohm’s Law And its Limitations MCQ	Meter Bridge MCQ	Potentiometer MCQ
Ohm’s Law And its Limitations QnA	Meter Bridge QnA	Potentiometer QnA

MCQs on Unit of Current

Ques 1. What is the unit of current?

Ampere
Volt
Ohm
Watt

Click here for the answer

Answer: a

Explanation: SI unit of electric current is Ampere. Ampere is the flow of electric charge at the rate of 1 coulomb per second. Ampere is denoted by the symbol A. Electric current is measured by a device called Ammeter.

Ques 2. Electric pressure is also called?

Resistance
Voltage
Wattage
Power

Click here for the answer

Answer: b

Explanation: Voltage is defined as the work needed per unit of charge to move a test charge between the two points. It is also called electric potential difference, electric pressure or electric tension is the difference in electric potential between two points.

Ques 3. Materials that offer less resistance and enables free movement of electrons is called?

Conductors
Insulators
Semiconductor
Inductors

Click here for the answer

Answer: a

Explanation: Conductors are materials that have free electrons which enables them to conduct electricity.

Ques 4. Which one is a poor conductor of electricity?

Iron
Silver
Wood
Tungsten

Click here for the answer

Answer: c

Explanation: Wood is a non-conductive material and thus acts as an insulator. Most of the metals are very good conductors of electricity.

Ques 5. The property by which a material allows current to pass through it is called?

Resistance
Reactance
Capacitance
Conductance

Click here for the answer

Answer: d

Explanation: Conductance is the property of a material to conduct electricity. Conductivity is amount or effective current a material can conduct. It is denoted by σ.

Ques 6. Conductance is the reciprocal of?

Resistance
Reactance
Capacitance
Conductance

Click here for the answer

Answer: a

Explanation: Conductance is the property of a material to conduct electricity. On the other hand, resistance is the property of a material to resist the electric current from passing through it.

Ques 7. Resistance varies inversely with?

Length
Cross section
Temperature
Resistivity

Click here for the answer

Answer: b

Explanation: Resistance is directly proportional to resistivity and length. It is inversely proportional to cross sectional area of the conductor.

R = \(\frac{pL}{A}\) p = resistivity, L = length, A = cross sectional area

Ques 8. Which instrument is used to detect electric current?

Galvanometer
Wattmeter
Rheostat
Voltmeter

Click here for the answer

Answer: a

Explanation: Galvanometer is a device used to measure electric current and intensity. It is indicated by a magnetic needle's movement or that of a coil in a magnetic field. A galvanometer is also used as an ammeter and a voltmeter.

Ques 9. Calculate the voltage across a 33 ohm resistor carrying 2A current.

33V
46V
66V
99V

Click here for the answer

Answer: c

Explanation: By Ohm’s law,

V = IR

V = 2 x 33

V = 66 volts

Ques 10. Calculate the resistance of a light bulb if its voltage is 5V and carries a current 10A.

0.2 Ohms
0.1 Ohms
0.5 Ohms
2 Ohms

Click here for the answer

Answer: c

Explanation: By Ohm’s law,

V = IR

R = V/I

R = 5/10

R = 0.5 Ohms

Check Out:

Class 12 Study Guides
Important Physics Formulae	Comparison Articles in Physics	NCERT Solutions for Class 12 Chemistry
Class 12 Maths Book	Class 12 Physics Book Pdf	CBSE Class 12 Physics Practicals
NCERT Solutions for Class 12 Maths	NCERT Solutions for Class 12 Physics	Important Physics Constants
SI Units in Physics	Important Physics MCQs	NCERT Class 12 PCMB Textbook
Class 12 PCMB Textbooks	Class 12 PCMB Notes	Class 12 Biology Book Pdf
NCERT Solutions for Class 12 Biology	Important Physics Derivations	Physics Study Material
Current Electricity Important Questions	Class 12 Physics Notes	Class 12 English Book Pdf

CBSE CLASS XII Related Questions

1.
Four long straight thin wires are held vertically at the corners A, B, C and D of a square of side \( a \), kept on a table and carry equal current \( I \). The wire at A carries current in upward direction whereas the current in the remaining wires flows in downward direction. The net magnetic field at the centre of the square will have the magnitude:
- \( \dfrac{\mu_0 I}{\pi a} \) and directed along OC
- \( \dfrac{\mu_0 I}{\pi a \sqrt{2}} \) and directed along OD
- \( \dfrac{\mu_0 I \sqrt{2}}{\pi a} \) and directed along OB
- \( \dfrac{2\mu_0 I}{\pi a} \) and directed along OA
View Solution
2.
A part of a wire carrying \( 2.0 \, \text{A} \) current and bent at \( 90^\circ \) at two points is placed in a region of uniform magnetic field \( \vec{B} = -0.50 \, \hat{k} \, \text{T} \), as shown in the figure. Calculate the magnitude of the net force acting on the wire.
View Solution
3.
In a Young's double-slit experiment, two waves each of intensity I superpose each other and produce an interference pattern. Prove that the resultant intensities at maxima and minima are 4I and zero respectively.
View Solution
4.
Consider a cylindrical conductor of length \( l \) and area of cross-section \( A \). Current \( I \) is maintained in the conductor and electrons drift with velocity \( \vec{v}_d \, (|\vec{v}_d| = \frac{eE}{m} \tau) \), where symbols have their usual meanings. Show that the conductivity of the material of the conductor is given by \[ \sigma = \frac{n e^2 \tau}{m}. \]
View Solution
5.
The figure represents the variation of the electric potential \( V \) at a point in a region of space as a function of its position along the x-axis. A charged particle will experience the maximum force at:
- P
- Q
- R
- S
View Solution
6.
Nuclides with the same number of neutrons are called:
- Isobars
- Isotones
- Isotopes
- Isomers
View Solution