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2020 26 questions

Q442020 · 6 Sept 2020 · Shift 1
An AC circuit has $R = 100 Ω$ , $C = 2 μ F$ and $L = 80 mH$ , connected in series. The quality factor of the circuit is :
1. A.20
2. B.2
3. C.0.5
4. D.400
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Answer: B
Q502020 · 6 Sept 2020 · Shift 1· Numerical answer
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Answer: 33
Q312020 · 6 Sept 2020 · Shift 2
A circuit to verify Ohm's law uses ammeter and voltmeter in series or parallel connected correctly to the resistor. In the circuit :
1. A.Ammeter is always connected in series and voltmeter in parallel
2. B.Both ammeter and voltmeter must be connected in series
3. C.Both ammeter and voltmeter must be connected in parallel
4. D.Ammeter is always used in parallel and voltmeter is series
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Answer: A
Q422020 · 6 Sept 2020 · Shift 2
1. A. $0.36 A$ from negative to positive terminal
2. B. $0.42 A$ from positive to negative terminal
3. C. $0.71 A$ from positive to negative terminal
4. D. $0.21 A$ from positive to negative terminal
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Answer: D
Q272020 · 3 Sept 2020 · Shift 1
1. A. $R = \frac{2 ρ}{π l} ln (\frac{b}{a})$
2. B. $R = \frac{ρ}{π l} ln (\frac{b}{a})$
3. C. $R = \frac{ρ}{2 π l} ln (\frac{b}{a})$
4. D. $R = \frac{ρ}{2 π l} (\frac{b}{a})$
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Answer: C
Q372020 · 3 Sept 2020 · Shift 1
1. A. $\frac{π ab B ω}{R}$
2. B. $\frac{π ^{2} a ^{2} b ^{2} B ^{2} ω ^{2}}{R}$
3. C. $\frac{π ^{2} a ^{2} b ^{2} B ^{2} ω ^{2}}{2 R}$
4. D.Zero
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Answer: C
Q382020 · 3 Sept 2020 · Shift 1
When a diode is forward biased, it has a voltage drop of 0.5 V. The safe limit of current through the diode is 10 mA. If a battery of emf 1.5 V is used in the circuit, the value of minimum resistance to be connected in series with the diode so that the current does not exceed the safe limit is
1. A. $50 Ω$
2. B. $200 Ω$
3. C. $300 Ω$
4. D. $100 Ω$
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Answer: D
Q322020 · 3 Sept 2020 · Shift 2
Which of the following will NOT be observed when a multimeter (operating in resistance measuring mode) probes connected across a component, are just reversed?
1. A.Multimeter shows NO deflection in both cases i.e. before and after reversing the probes if the chosen component is metal wire.
2. B.Multimeter shows a deflection, accompanied by a splash of light out of connected component in one direction and NO deflection on reversing the probes if the chosen component is LED.
3. C.Multimeter shows an equal deflection in both cases i.e. before and after reversing the probes if the chosen component is resistor.
4. D.Multimeter shows NO deflection in both cases i.e. before and after reversing the probes if the chosen component is capacitor.
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Answer: D
Q342020 · 3 Sept 2020 · Shift 2
Two resistors $400 Ω$ and $800 Ω$ are connected in series across a 6 V battery. The potential difference measured by a voltmeter of $10 kΩ$ across $400 Ω$ resistor is close to :
1. A.2.05 V
2. B.1.95 V
3. C.2 V
4. D.1.8 V
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Answer: B
Q392020 · 2 Sept 2020 · Shift 1
Consider four conducting materials copper, tungsten, mercury and aluminium with resistivity $ρ_{C}, ρ_{T}$ , $ρ_{M}$ and $ρ_{A}$ respectively. Then :
1. A. $ρ_{C} > ρ_{A} > ρ_{T}$
2. B. $ρ_{M} > ρ_{A} > ρ_{C}$
3. C. $ρ_{A} > ρ_{T} > ρ_{C}$
4. D. $ρ_{A} > ρ_{M} > ρ_{C}$
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Answer: B
Q422020 · 2 Sept 2020 · Shift 2
1. A.1, 1, 0, 1
2. B.0, 1, 0, 0
3. C.1, 0, 1, 1
4. D.0, 0, 1, 0
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Answer: D
Q452020 · 2 Sept 2020 · Shift 2
1. A.0.04 V/cm
2. B.0.01 V/cm
3. C.0.02 V/cm
4. D.0.03 V/cm
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Answer: C
Q492020 · 2 Sept 2020 · Shift 2· Numerical answer
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Answer: 8
Q402020 · 9 Jan 2020 · Shift 1
1. A.4 A
2. B.2 A
3. C.zero
4. D.0.4 A
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Answer: B
Q502020 · 9 Jan 2020 · Shift 1· Numerical answer
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Answer: 12
Q472020 · 9 Jan 2020 · Shift 2· Numerical answer
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Answer: 40
Q412020 · 8 Jan 2020 · Shift 1
1. A. $A.B$
2. B. $\overset{ˉ}{A} + \overset{ˉ}{B}$
3. C. $\overset{ˉ}{A} . \overset{ˉ}{B}$
4. D. $A + B$
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Answer: C
Q452020 · 8 Jan 2020 · Shift 1
The length of a potentiometer wire is 1200 cm and it carries a current of 60 mA. For a cell of emf 5V and internal resistance of $20 Ω$ , the null point on it is found to be a 1000 cm. The resistance of whole wire is :
1. A. $80 Ω$
2. B. $60 Ω$
3. C. $120 Ω$
4. D. $100 Ω$
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Answer: D
Q462020 · 8 Jan 2020 · Shift 1· Numerical answer
Four resistances of $15 Ω$ , $12 Ω$ , $4 Ω$ and $10 Ω$ are connected respectively in cyclic order to form Wheatstone's network. The resistance that is to be connected in parallel with the resistance of $10 Ω$ to balance the network is _______ $Ω$ .
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Answer: 10
Q292020 · 8 Jan 2020 · Shift 2
A galvanometer having a coil resistance $100 Ω$ gives a full scale deflection when a current of 1 mA is passed through it. What is the value of the resistance which can convert this galvanometer into a voltmeter giving full scale deflection for a potential difference of 10 V?
1. A. $8.9 k Ω$
2. B. $10 k Ω$
3. C. $9.9 k Ω$
4. D. $7.9 k Ω$
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Answer: C
Q342020 · 8 Jan 2020 · Shift 2
1. A. $\frac{ε L}{e R ^{2}}$
2. B. $\frac{ε L}{R ^{2}}$
3. C. $\frac{ε L}{R ^{2}} (1 - \frac{1}{e})$
4. D. $\frac{εR}{e L ^{2}}$
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Answer: A
Q442020 · 8 Jan 2020 · Shift 2
1. A.toggles between 0 and 1
2. B.1
3. C.will not execute
4. D.0
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Answer: D
Q502020 · 8 Jan 2020 · Shift 2· Numerical answer
The series combination of two batteries, both of the same emf 10 V, but different internal resistance of $20 Ω$ and $5 Ω$ , is connected to the parallel combination of two resistors $30 Ω$ and $R Ω$ . The voltage difference across the battery of internal resistance $20 Ω$ is zero, the value of R (in $Ω$ ) is : _______
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Answer: 30
Q392020 · 7 Jan 2020 · Shift 1
1. A.0.4
2. B.0.25
3. C.0.2
4. D.0.5
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Answer: C
Q302020 · 7 Jan 2020 · Shift 2
An emf of 20 V is applied at time t = 0 to a circuit containing in series 10 mH inductor and $5 Ω$ resistor. The ratio of the currents at time $t = \infty$ and at $t = 40 s$ is close to : (Take $e^{2} = 7.389$ )
1. A.1.06
2. B.0.84
3. C.1.15
4. D.1.46
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Answer: A