# Multiple choice question for engineering

## Set 1

1. Which of the following is not an expression power?

a) P=VI

b) P=I^{2}R

c) P=V^{2}/R

d) All of the mentioned

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^{2}/R and writing V in terms of I, we get P=I

^{2}r.

2. Which of the following statements are true?

a) Power is proportional to Voltage

b) Power is proportional to current

c) Neither of the statements are right

c) Both the statements are right

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3. A 250V bulb passes a current of 0.3A. Calculate the power in the lamp.

a) 75W

b) 50W

c) 25W

d) 90W

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4. Kilowatt-hour(kWh) is a unit of?

a) Current

b) Power

c) Energy

d) Resistance

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5. Calculate the power in the 20 ohm resistance.

a) 2000kW

b) 2kW

c) 200kW

d) 2W

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^{2}/R= 200

^{2}/20=2000W=2kW.

6. A current of 5A flows in a resistor of 2 ohm. Calculate the power in the resistor and the energy dissipated in 300 seconds.

a) 15kJ

b) 15000kJ

c)1500J

d) 15J

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^{2}R =5

^{2}*2=50W. E= Pt=50*300=15000J=15kJ.

7. Calculate the power across each 20 ohm resistance.

a) 1000W, 1000W

b) 500W, 500W

c) 1000kW, 1000kW

d) 500kW, 500kW

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^{2}R=5

^{2}*20=500W. Since both the resistors have a resistance of 20 ohm, the power across both is the same.

8. Calculate the power across each 10 ohm resistance.

a) 1000kW, 1000kW

b) 1kW, 1kW

c) 100W, 100W

d) 100kW, 100kW

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9. Calculate the work done in a resistor of 20 ohm carrying 5A of current in 3 hours.

a) 1.5J

b) 15J

c) 1.5kWh

d) 15kWh

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^{2}R=5

^{2}*20=500W=0.5kW. To find Work done: W=Pt=0.5*3=1.5kWh.

10. The SI unit of power is?

a) kW(kilo-watt)

b) J/s(joules per second)

c) Ws(watt-second)

d) J/h(joules per hour

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## Set 2

1. Quality factor is also known as _________

a) Voltage magnification

b) Current magnification

c) Resistance magnification

d) Impedance magnification

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2. At resonance condition, voltage across the capacitor and inductor is _________ the source voltage.

a) Greater than

b) Less than

c) Equal to

d) Much less than

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3. What is the voltage across the capacitor when the source voltage is 100V and the Q factor is 10.

a) 100V

b) 10V

c) 1000V

d) 0V

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4. Find the Q factor when the voltage across the capacitor is 1000V and the source voltage is 100V.

a) 10

b) 20

c) 30

d) 40

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5. Find the source voltage when the voltage across the capacitor is 1000V and the Q factor is 10.

a) 10V

b) 200V

c) 100V

d) 90V

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6. What is the voltage across the inductor when the source voltage is 200V and the Q factor is 10.

a) 100V

b) 20V

c) 2000V

d) 0V

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7. Find the Q factor when the voltage across the indictor is 2000V and the source voltage is 100V.

a) 10

b) 20

c) 30

d) 40

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8. Find the source voltage when the voltage across the inductor is 2000V and the Q factor is 20.

a) 10V

b) 200V

c) 100V

d) 90V

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9. What happens to the voltage across the capacitor when the Q factor increases?

a) Increases

b) Decreases

c) Remains the same

d) Becomes zero

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10. What happens to the voltage across the inductor when the Q factor decreases?

a) Increases

b) Decreases

c) Remains the same

d) Becomes zero

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## Set 3

1. Permeability of free space is also known as _________

a) Magnetic constant

b) Electric constant

c) Electrostatic constant

d) Magnetostatic constant

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2. A substance whose permeability is less than the permeability of free space is?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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3. Which, among the following, have negative susceptibility?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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4. Which, among the following, have positive susceptibility?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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5. A substance whose permeability is more than the permeability of free space is?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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6. The unit for permeability of free space is?

a) Henry

b) Henry-m

c) Henry/m

d) Henry/m^{2}

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7. Which, among the following, is a correct expression for ∫0.

a) ∫0=BH

b) ∫0=B/H

c) ∫0=H/B

d) ∫0=BH^{2}

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8. Calculate the magnetic flux density if the magnetic field strength is 2A/m.

a) 4*pi/10^{-7}T

b) 8*pi/10^{-7}T

c) 10*pi/10^{-7}T

d) 12*pi/10^{-7}T

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^{-7}T.

9. Calculate the magnetic field strength if the magnetic flux density is 4*piT.

a) 10^{-7}/16*pi^{2}A/m

b) 10^{-7}A/m

c) 10^{7}A/m

d) 10^{-7}A

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^{7}A/m.

10. Calculate the magnetic flux density if the magnetic field strength is 3A/m.

a) 4*pi/10^{-7}T

b) 8*pi/10^{-7}T

c) 10*pi/10^{-7}T

d) 12*pi/10^{-7}T

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^{-7}T.

## Set 4

1. What is the unit for relative permeability?

a) H-m

b) H/m

c) H^{2}/m

d) No unit

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2. Which of the following expressions is correct with respect to relative permeability?

a) B=∫r∫0/H

b) B=∫r∫0H

c) B=∫r/∫0H

d) B=∫r∫0/H^{2}

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3. A substance whose relative permeability is less than the permeability of free space is?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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4. A substance whose relative permeability is more than the permeability of free space is?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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5. Diamagnetic substances have relative permeability_____________

a) Greater than 1

b) Less than 1

c) Equal to 1

d) Zero

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6. Paramagnetic substances have relative permeability_____________

a) Greater than 1

b) Less than 1

c) Equal to 1

d) Zero

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7. As the temperature increases up to the Curie temperature, the relative susceptibility of ferromagnetic materials?

a) Increases

b) Decreases

c) Remains constant

d) Becomes zero

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8. As the temperature increases beyond the Curie temperature, the relative susceptibility of ferromagnetic materials?

a) Increases

b) Decreases

c) Remains constant

d) Becomes zero

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9. Which, among the following, have positive susceptibility?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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10. Which, among the following, have negative susceptibility?

a) Diamagnetic

b) Paramagnetic

c) Ferromagnetic

d) Not a magnetic substance

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## Set 5

1. In order to obtain a high value for capacitance the permittivity of the dielectric medium should be?

a) Low

b) High

c) Zero

d) Unity

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2. Find the capacitance of a capacitor whose area of cross section of the plates is 4m^{2} and distance of separation between the plates is 2m. The capacitor is placed in vacuum.

a) 1.77*10^{-11}F

b) 1.34*10^{-11}F

c) 2.33*10^{-11}F

d) 5.65*10^{-11}F

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^{-12}. Therefore, C=8.85*10

^{-12}*4/2= 1.77*10

^{-12}F.

3. What is relative permittivity?

a) Equal to absolute permittivity

b) Ratio of actual permittivity to absolute permittivity

c) Ratio of absolute permittivity to actual permittivity

d) Equal to actual permittivity

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4. What happens to relative permittivity when actual permittivity decreases?

a) Increases

b) Decreases

c) Remains the same

d) Becomes zero

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5. What is the relative permittivity when the actual permittivity is 4F/m?

a) 4.57*10^{-11}

b) 4.57*10^{12}

c) 4.57*10^{11}

d) 4.57*10^{-12}

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^{-12})= 4.57*10

^{11}.

6. What happens to absolute permittivity when relative permittivity increases?

a) Increases

b) Decreases

c) Remains the same

d) Becomes zero

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7. Calculate the actual permittivity of a medium whose relative permittivity is 5.

a) 4.43*10^{-11}F/m

b) 4.43*10^{-12}F/m

c) 4.43*10^{11}F/m

d) 4.43*10^{12}F/m

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^{-11}F/m.

8. What is the unit for relative permittivity?

a) F/m

b) Fm

c) F/m^{2}

d) No unit

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9. Which, among the following, will be unity in free space?

a) Absolute permittivity

b) Relative permittivity

c) Actual permittivity

d) Both absolute and relative permittivity

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^{-12}F/m. Actual permittivity is the product of relative permittivity and absolute permittivity.

10. Which, among the following, do not have any unit?

a) Absolute permittivity

b) Relative permittivity

c) Actual permittivity

d) Both absolute and relative permittivity