MCQs On Direct Current (DC) Electrical Circuit

1) A DC circuit has ___________ as a load.

- Resistance
- Inductance
- Capacitance
- All of the above

2) The purpose of load in an electric circuit is to

- Increase the circuit current
- Utilize electrical energy
- Decrease the circuit current
- None of the above

3) Electrical appliances are not connected in series because

- Series circuit is complicated
- Power loss is more
- Appliances have different current ratings
- None of the above

4) Electrical appliances are connected in parallel because it

- Is a simple circuit
- Draws less current
- Results in reduced power loss
- Makes the operation of appliances independent of each other

5) Three resistance 14.5 Ω, 25.5 Ω and 60 Ω are connected in series across 200 V. What will be the voltage drop across 14.5 Ω

- 29 V
- 13.5 V
- 14 V
- 18 V

6) Two bulbs B_{1} 100 W, 200 V and B_{2} 40 W, 200 V are connected in series across 200 V battery, the total circuit resistance will be

- 1000 Ω
- 400 Ω
- 1400 Ω
- 135 Ω

7) When the number of resistance are connected in parallel, the total resistance is

- Greater than the smallest resistance
- Between the smallest and greatest resistance
- Less than the smallest resistance
- None of the above

8) When cells are arranged in parallel

- The current capacity increases
- The current capacity decreases
- The e.m.f decreases
- The e.m.f increases

9) A cell of e.m.f E is connected across a resistance R. The potential difference between the terminals of the cell is found to be V. The instant resistance of the cell is

- 2(E – V)V/r
- 2(E – V)r/E
- (E – V)r
- ((E – V)/V)r

10) An external resistance R is connected to a cell of internal resistance r. The maximum current flows in the external resistance when

- R < r
- R > r
- R = r
- None of the above

11) A wire has a resistance of 12 Ω. It is bent in the form of a circle. The effective resistance between the two points on any diameter of the circle is

- 6 Ω
- 3 Ω
- 12 Ω
- 24 Ω

12) The total resistance of circuit by connecting 50 resistance of 1/4 Ω in parallel is

- 50/4 Ω
- 4/50 Ω
- 200 Ω
- 1/200 Ω

13) The internal resistance of a cell of e.m.f 2 V is 0.1 Ω. It is connected to a resistance of 3.9 Ω. The voltage across the cell is

- 0.5 V
- 1.95 V
- 1.9 V
- 2 V

14) Three 2 Ω resistors are connected to form a triangle. The resistance between any two corners is

- 6 Ω
- 2 Ω
- (3/4) Ω
- (4/3) Ω

15) A cell with zero internal resistance and e.m.f of 2 V is connected across 2, 3 and 5 Ω. The potential difference across 3 Ω resistor will be

- (2/3) V
- 0.6 V
- 3 V
- 6 V

16) Two bulbs 200 W and 100 W are connected across 220 V supply in series. Find the power consumed by both bulbs

- 300 W
- 200 W
- 66 W
- 50 W

17) An electrical fan and heater are marked as 100 W and 1000 W respectively at 220 V supply. What will be the resistance of heater

- Zero
- Greater than that of the fan
- Less than that of the fan
- Equal to that of the fan

18) If the internal resistance of the cell connected in circuit is greater than the external circuit, higher current will be obtained by arranging cell in ______

- Series
- Parallel
- Series-Parallel
- Any connection

- Current density
- Reactance
- Resistivity
- Inductance

- 5 V
- 50 V
- 500 V
- 50 kV

21) The specific resistance of a metallic conductor ________ with the rise in temperature

- Increases
- Decreases
- Remains same
- Decreases first than start increases

- Zero
- Negative
- Positive
- None of the above

- Positive
- Negative
- Almost zero
- None of the above

- 5 C
- 0.5 C
- 50 C
- 500 C

- Two times
- Half
- Sixteen times
- Eight times

- Positive
- Negative
- Zero
- None of the above

- 1 ms
^{-1} - 10 ms
^{-3} - 10
^{6}ms^{-1} - 3×10
^{8}ms^{-1}

^{2}in area of cross-section is 1.6×10

^{-8}Ω. Its specific resistance will be

- 1.6×10
^{-8}Ωm - 3.2×10
^{-8}Ωm - 6.4×10
^{-8}Ωm - 0.16×10
^{-8}Ωm

- Length of the material
- Cross-sectional area of the material
- Volume of the material
- Nature of the material and temperature

^{o}is stretched till its length is increased ‘n’ times of its original length. Its resistance will now be

- n
^{2}R^{o} - R
^{o}/ n^{2} - nR
^{o} - n
^{3}R^{o}

^{-8}Ωm. What will be the resistance of a hollow pipe of the material of length 1 m and having inner and outer radii of 10 cm and 20 cm respectively.

- 2.0 × 10
^{-4}Ω - 2.1 × 10
^{-7}Ω - 2.0 × 10
^{-5}Ω - 2.0 × 10
^{-3}Ω

- Copper wire
- Carbon resistance
- Aluminium wire
- Tungsten wire
- All of the above

- 0.1 %
- 0.2 %
- 0.3 %
- 0.4 %

- Begins to laugh
- Gets shocked
- Is excited
- Becomes insensitive to pain

- 1154 K
- 1100 K
- 1400 K
- 1127 K

- Quantity of electricity
- Energy
- Power
- Conductivity

- 1 Ω
- 2 Ω
- 3 Ω
- 4 Ω

^{0}of a conductor is 1/236 per °C. The value of α

^{18}will be

- 1/218 per °C
- 1/244 per °C
- 1/254 per °C
- 1/264 per °C

^{0}of a conductor is 1/255 per °C. The value of α

^{20}will be

- 1/300 per °C
- 1/230 per °C
- 1/250 per °C
- 1/265 per °C

^{50}of a conductor is 1/230 per °C. The value of α

^{0}will be

- 1/180 per °C
- 1/280 per °C
- 1/380 per °C
- 1/250 per °C

41) The number of free electrons passing through the filament of an electric bulb in one hour when the current through the current through it is 0.32 A filament will

- 3 × 10
^{22} - 2× 10
^{26} - 7.2 × 10
^{19} - 3 × 10
^{21}

- Carbon
- Constantan
- Copper
- Silver

- Very good conductor
- Moderately good conductor
- Insulator
- None of the above

- 0.1 Ω
- 20 Ω
- 1/20 Ω
- 200 Ω

- 1/9 times
- 3 times
- 9 times
- 1/3 times

- 100 V
- 50 V
- 150 V
- 200 V

_{1}dissipates the power P when connected to a certain generator. If resistance R

_{2}is put in series with R

_{1}, the power dissipated by R

_{1}

- Decreases
- Increases
- Remains the same
- Any of the above depending upon the values of R
_{1}and R_{2}

- Fully obeyed
- Partially obeyed
- There is no relation there between current and P.D
- None of the above

_{1}and R

_{2}then

- R
_{1}= 2 R_{2} - R
_{2}= 2 R_{1} - R
_{2}= 4 R_{1} - R
_{1}= 4 R_{2}

- 10 Ω
- 12.1 Ω
- 9 Ω
- 11 Ω

^{20}electrons each having a charge of 1.6×10

^{-19}C pass from a point X to a point Y in 0.1 seconds. The current flowing is

- 16 A
- 1.6 A
- 160 A
- 1 A

- Capacity
- Potential
- Charge
- None of the above

- 4 Ω
- 0.5 Ω
- 1.2 Ω
- 0.121 Ω

- 48 × 10
^{-8}Ωm - 40 × 10
^{8}Ωm - 4 × 10
^{-6}Ωm - 4.8 × 10
^{-8}Ωm

- Power
- Energy
- E.M.F
- Charge

- 6%
- 3%
- 9%
- 12%

_{A}and R

_{B}respectively with R

_{A}<R

_{B}. The resistivity of their materials are ρA and ρB. Then

- ρA < ρB
- ρA = ρB
- ρA < ρB
- Insufficient information

- Increased
- Decreased
- Remains constant
- May increased or decreased

- 10 Ω
- 20 Ω
- 5 Ω
- 40 Ω

^{6}m/s. The electric current of a point on the circle is

- 1×10
^{-12}A - 4×10
^{-7}A - 2×10
^{-6}A - None of the above

61) The resistance of a human body is about

- 200 Ω
- 1000 Ω
- 25 Ω
- 10 Ω

- Zero
- Positive
- Negative
- None of the above

- 80 m
- 40 m
- 20 m
- 24 m

- 1 μ mho
- 10 μ mho
- 100 μ mho
- None of the above

- 20 μS
- 14.81 μS
- 18.71 μS
- 24.5 μS

- 50 V
- 300 V
- 150 V
- 75 V

- 5.4 kWh
- 2.89 kWh
- 1.89 kWh
- 10.89 kWh

- V
^{2}G - V
^{2}/ G - G
^{2}V - G
^{2}/ V

- 55 V
- 110 V
- 45 V
- 50 V

i = 5 cos πt A

The~~ ~~power delivered to the element at t = 3 ms when the voltage across the element is 3t is given by

- 18.43 W
- 26.4 W
- 53.48 W
- 63.28 W

^{2}is carrying a current of 10 A. If the number density of conduction electrons is 10

^{-28}m

^{-3}. The drift velocity of conduction electrons is

- 1 / 160 ms
^{-1} - 1 / 20 ms
^{-1} - 1 / 30 ms
^{-1} - 1 / 80 ms
^{-1}

- 2 × 10
^{-6}Ω - 0.8 × 10
^{-6}Ω - 1.6 × 10 Ω
- 4 × 10
^{-6}Ω

- 1/3 α
_{o}°C - 1/α
_{o}°C - 1/2 α
_{o}°C - 1/6 α
_{o}°C

- R/4
- R/2
- R
- 2R

_{A}= 600 Ω and R

_{B}= 100 Ω. The number of times A is longer than B is

- 6
- 2
- 4
- 5

- Length
- Material
- Cross-sectional area
- None of the above

- Charge
- Energy
- Momentum
- Mass

- 184000
- 18400
- 1840
- 184

- Joule / Second
- Ampere / Volt
- Ampere x Volts
- (Ampere)
^{2}x Ohm

- 36 x 10
^{5}watt - 36 x 10
^{5}ergs - 36 x 10
^{5}joules - 36 x 10
^{5}B.T.U

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