Wednesday, 21 September 2022

Current Electricity : MCQ on Current Electricity

The branch of Physics, which deals with the study of charges in motion is called Current Electricity.

Electric Current :- It is defined as the rate of flow of charge across any cross-section of conductor.

If a charge ‘q’ flows across any cross-section in ‘t’ second ,current ‘i’ is given by I= q/t

I= ne/t

Q1 S.I Unit of Electric motive force is

• Coulomb
• Ampere
• Volt
• Coulomb/Ampere

• Volt

Q2 Electromotive force .............potential difference.

• may be equals to
• may be greater than
• both (a) and (b)
• none of these

both (a) and (b)

Q3 A wire is carrying a current. Is it charged?

• Yes,
• No

No

(Electric current is the flow of free electrons in the conductors. At any instant, the no. of electrons leaving the wire is always equal to the no. of electrons flowing from the battery into it. Hence the net charge on the wire is zero.)

Q4 Electric current is a .................. quantity.

• Scalar
• Vector
• Tensor
• None of the above

• Scalar

Q5 S.I Unit of Electric current is ...

• Coulomb
• Ampere
• Tesla
• Coulomb/Ampere

• Ampere

Q6 One Ampere =.................................... stat ampere.

• 3x10^{19}
• 3x10^{9}
• 2.25x 10^{19}
• None of these

• 3x10^{19}

Q7 How many electrons passes in one second when current is 1A.

• 5.26 × 10^{18}
• 6.25 × 10^{25}
• 5.26 × 10^{19}
• 6.25 × 10^{19}

• 6.25 × 10^{25}

Q8 The relaxation time in conductors:

• Increases with increase in temperature
• Decreases with the increases of temperature
• It does not depend on temperature
• Changes suddenly at 400 Kelvin.

• Decreases with the increases of temperature.

Q9 According to Ohm’s Law

• V is directly proportional to I
• V is inversely proportional to I
• V is directly proportional to √I
• All of the above.

• V is directly proportional to I

Q10 Ohm's law is applicable to

• Semiconductors
• Vacuum tubes
• Carbon resistors
• None of these

• None of these