Courses

# Test: Analysis Of Growth & Analysis Of Decay

## 20 Questions MCQ Test Basic Electrical Technology | Test: Analysis Of Growth & Analysis Of Decay

Description
This mock test of Test: Analysis Of Growth & Analysis Of Decay for Electrical Engineering (EE) helps you for every Electrical Engineering (EE) entrance exam. This contains 20 Multiple Choice Questions for Electrical Engineering (EE) Test: Analysis Of Growth & Analysis Of Decay (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Analysis Of Growth & Analysis Of Decay quiz give you a good mix of easy questions and tough questions. Electrical Engineering (EE) students definitely take this Test: Analysis Of Growth & Analysis Of Decay exercise for a better result in the exam. You can find other Test: Analysis Of Growth & Analysis Of Decay extra questions, long questions & short questions for Electrical Engineering (EE) on EduRev as well by searching above.
QUESTION: 1

### What is the total applied voltage in an inductive circuit?

Solution:

The total voltage in an inductive circuit is the sum of the voltage due to the resistor which is Ri and the voltage due to the inductor which is Ldi/dt. Hence V=Ri+Ldi/dt.

QUESTION: 2

### What is Helmholtz equation?

Solution:

Helmholtz equation is an equation which gives the formula for the growth in an inductive circuit. Hence the Helmholtz formula is: i=I(1-e-Rt/L).

QUESTION: 3

### Among the following, which is the right formula for growth in an inductive circuit?

Solution:

The correct formula for growth in an inductive circuit is VL=V(1-e-t /time constant). As the time increases, the current in the inductor increases hence the voltage also increases.

QUESTION: 4

The charging time constant of a circuit consisting of an inductor is the time taken for the voltage in the inductor to become __________% of the initial voltage.

Solution:

We know that: V=V0(1-e-t /time constant).
When time constant=t, we have: V=V0(1-e-1)= 0.63*V0.
Hence the time constant is the time taken for the charge in an inductive circuit to become 0.63 times its initial charge.

QUESTION: 5

What is the time constant of an inductive circuit?

Solution:

The time constant in an inductive circuit is the time taken for the voltage across the inductor to become 63 percent of its initial value. It is given by: Time constant= L/R.

QUESTION: 6

A coil has a resistance of 4 ohm and an inductance of 2H. Calculate its time constant.

Solution:

The expression for time constant in an inductive circuit is:
Time constant= L/R
Substituting the values from the question given, we get time constant= 0.5s.

QUESTION: 7

A coil has a resistance of 4 ohm and an inductance of 2H. It is connected to a 20V dc supply. Calculate the final value of current in the circuit.

Solution:

The final value of current in the circuit is:
I=V/R= 5A.

QUESTION: 8

A coil has a resistance of 4 ohm and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of current 1s after the switch is closed.

Solution:

We know that:
i=I(1-eRt/L)
I=V/R=5A
Substituting the remaining values from the given question, we get i=4.32A.

QUESTION: 9

What happens to the inductance when the current in the coil becomes double its original value?

Solution:

The formula for magnetic field strength in a coil is:
H=iN/l
The inductance is: directly proportional to magnetic field strength, hence as the current value doubles, the inductance also doubles.

QUESTION: 10

Calculate the inductance in an inductive circuit whose time constant is 2s and the resistance is 5 ohm.

Solution:

We know that: Time constant= L/R
Substituting the values from the given question, we get L=10H.

QUESTION: 11

What is the time constant of an inductive circuit?

Solution:

The time constant in an inductive circuit is the time taken for the voltage across the inductor to become 63 percent of its initial value. It is given by: Time constant= L/R.

QUESTION: 12

Among the following, which is the right formula for decay in an inductive circuit?

Solution:

The correct formula for decay in an inductive circuit is i=I(e-t /time constant). As the time increases, the current in the inductor decreases, the voltage also increases.

QUESTION: 13

The discharging time constant of a circuit consisting of an inductor is the time taken for the voltage in the inductor to become __________% of the initial voltage.

Solution:

We know that: V=V0(e-t/time constant).
When time constant=t, we have: V=V0(e-1)= 0.36*V0.
Hence the time constant is the time taken for the charge in an inductive circuit to become 0.36 times its initial charge.

QUESTION: 14

The discharging time constant of a circuit consisting of an inductor is the time taken for the voltage in the inductor to become __________% of the initial voltage.

Solution:

We know that: V=V0(e-t/time constant).
When time constant=t, we have: V=V0(e-1)= 0.36*V0.
Hence the time constant is the time taken for the charge in an inductive circuit to become 0.36 times its initial charge.

QUESTION: 15

In case of Inductive circuit, Frequency is ______________ to the current.

Solution:

Inductance is inversely proportional to current since, as the inductance increases, current decreases.

QUESTION: 16

Calculate the time constant of an inductive circuit having resistance 5 ohm and inductance 10H.

Solution:

We know that: Time constant= L/R
Substituting the values from the given question, we get time constant= 2s.

QUESTION: 17

Calculate the inductance in an inductive circuit whose time constant is 2 and the resistance is 5 ohm.

Solution:

We know that: Time constant= L/R
Substituting the values from the given question, we get L=10H.

QUESTION: 18

A coil has a resistance of 4 ohm and an inductance of 2H. It is connected to a 20V dc supply. Calculate the final value of current in the circuit.

Solution:

The final value of current in the circuit is:
I=V/R= 5A.

QUESTION: 19

What happens to the inductance when the current in the coil becomes double its original value?

Solution:

The formula for magnetic field strength in a coil is:
H=iN/l
The inductance is: directly proportional to magnetic field strength, hence as the current value doubles, the inductance also doubles.

QUESTION: 20

What is the total applied voltage in an inductive circuit?

Solution:

The total voltage in an inductive circuit is the sum of the voltage due to the resistor which is Ri and the voltage due to the inductor which is Ldi/dt. Hence V=Ri+Ldi/dt.