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2021 49 questions

Q562021 · 27 Jul 2021 · Shift 2· Numerical answer
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Answer: 1
Q492021 · 25 Jul 2021 · Shift 1
1. A.5 V
2. B.2.25 V
3. C.6 V
4. D.2.75 V
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Answer: A
Q532021 · 25 Jul 2021 · Shift 1· Numerical answer
An inductor of 10 mH is connected to a 20V battery through a resistor of $10 kΩ$ and a switch. After a long time, when maximum current is set up in the circuit, the current is switched off. The current in the circuit after $1 μ s$ is $\frac{x}{100}$ mA. Then x is equal to ____. (Take $e^{- 1} = 0.37$ )
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Answer: 74
Q542021 · 25 Jul 2021 · Shift 1· Numerical answer
A circular conducting coil of radius 1 m is being heated by the change of magnetic field $B$ passing perpendicular to the plane in which the coil is laid. The resistance of the coil is $2 μ Ω$ . The magnetic field is slowly switched off such that its magnitude changes in time as $B = \frac{4}{π} \times 1 0^{- 3} T (1 - \frac{t}{100})$ The energy dissipated by the coil before the magnetic field is switched off completely is E = ____ mJ.
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Answer: 80
Q582021 · 25 Jul 2021 · Shift 1· Numerical answer
An electric bulb rated as 200 W at 100 V is used in a circuit having 200 V supply. The resistance 'R' that must be put in series with the bulb so that the bulb delivers the same power is ____ $Ω$ .
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Answer: 50
Q362021 · 25 Jul 2021 · Shift 2
A $10 Ω$ resistance is connected across $220 V - 50 Hz$ AC supply. The time taken by the current to change from its maximum value to the rms value is :
1. A.2.5 ms
2. B.1.5 ms
3. C.3.0 ms
4. D.4.5 ms
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Answer: A
Q492021 · 25 Jul 2021 · Shift 2
1. A. $\frac{5}{3}$
2. B. $\frac{8}{5}$
3. C. $\frac{4}{3}$
4. D. $\frac{3}{2}$
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Answer: A
Q502021 · 25 Jul 2021 · Shift 2
1. A.10 V
2. B.5 V
3. C. $\frac{40}{9}$ V
4. D. $\frac{40}{11}$ V
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Answer: C
Q532021 · 25 Jul 2021 · Shift 2· Numerical answer
A $16 Ω$ wire is bent to form a square loop. A 9V supply having internal resistance of $1Ω$ is connected across one of its sides. The potential drop across the diagonals of the square loop is ____ $\times 1 0^{- 1}$ V
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Answer: 45
Q542021 · 25 Jul 2021 · Shift 2· Numerical answer
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Answer: 500
Q322021 · 22 Jul 2021 · Shift 2
1. A. $0.0858 m Ω$
2. B. $1.420 m Ω$
3. C. $0.858 m Ω$
4. D. $2.170 m Ω$
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Answer: C
Q422021 · 22 Jul 2021 · Shift 2
Match List - I with List - II | | List - I | | List - II | |---|---|---|---| | (a) | $ω L > \frac{1}{ω C}$ | (i) | Current is in phase with emf | | (b) | $ω L = \frac{1}{ω C}$ | (ii) | Current lags behind the applied emf | | (c) | $ω L < \frac{1}{ω C}$ | (iii) | Maximum current occurs | | (d) | Resonant frequency | (iv) | Current leads the emf | Choose the correct answer from the options given below
1. A.a(ii), b(i), c(iv), d(iii)
2. B.a(ii), b(i), c(iii), d(iv)
3. C.a(iii), b(i), c(iv), d(ii)
4. D.a(iv), b(iii), c(ii), d(i)
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Answer: A
Q542021 · 22 Jul 2021 · Shift 2· Numerical answer
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Answer: 500
Q572021 · 22 Jul 2021 · Shift 2· Numerical answer
In an electric circuit, a cell of certain emf provides a potential difference of $1.25 V$ across a load resistance of $5Ω$ . However, it provides a potential difference of $1 V$ across a load resistance of $2Ω$ . The emf of the cell is given by $\frac{x}{10} V$ . Then the value of x is ________.
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Answer: 15
Q322021 · 20 Jul 2021 · Shift 1
1. A. $25 mA$
2. B. $0.1 A$
3. C. $0.15 A$
4. D. $0.05 A$
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Answer: A
Q402021 · 20 Jul 2021 · Shift 1
1. A. $4 A$
2. B. $8 A$
3. C. $10 A$
4. D. $6 A$
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Answer: C
Q402021 · 18 Mar 2021 · Shift 1
In the experiment of Ohm's law, a potential difference of 5.0 V is applied across the end of a conductor of length 10.0 cm and diameter of 5.00 mm. The measured current in the conductor is 2.00 A. The maximum permissible percentage error in the resistivity of the conductor is :
1. A.3.9
2. B.8.4
3. C.7.5
4. D.3.0
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Answer: A
Q412021 · 18 Mar 2021 · Shift 1
In a series LCR resonance circuit, if we change the resistance only, from a lower to higher value :
1. A.The bandwidth of resonance circuit will increase.
2. B.The resonance frequency will increase.
3. C.The quality factor will increase.
4. D.The quality factor and the resonance frequency will remain constant.
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Answer: A
Q422021 · 18 Mar 2021 · Shift 1
An AC source rated 220 V, 50 Hz is connected to a resistor. The time taken by the current to change from its maximum to the rms value is :
1. A.2.5 ms
2. B.25 ms
3. C.2.5 s
4. D.0.25 ms
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Answer: A
Q532021 · 18 Mar 2021 · Shift 1· Numerical answer
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Answer: 70
Q602021 · 18 Mar 2021 · Shift 1· Numerical answer
An npn transistor operates as a common emitter amplifier with a power gain of $1 0^{6}$ . The input circuit resistance is $100Ω$ and the output load resistance is $10 K Ω$ . The common emitter current gain ' $β$ ' will be _______. (Round off to the Nearest Integer).
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Answer: 100
Q412021 · 18 Mar 2021 · Shift 2
The time taken for the magnetic energy to reach 25% of its maximum value, when a solenoid of resistance R, inductance L is connected to a battery, is :
1. A.infinite
2. B. $\frac{L}{R} ln 10$
3. C. $\frac{L}{R} ln 2$
4. D. $\frac{L}{R} ln 5$
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Answer: C
Q512021 · 18 Mar 2021 · Shift 2· Numerical answer
Two wires of same length and thickness having specific resistances $6 Ω cm$ and $3 Ω cm$ respectively are connected in parallel. The effective resistivity is $ρ Ω cm$ . The value of $ρ$ , to the nearest integer, is ____.
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Answer: 4
Q522021 · 18 Mar 2021 · Shift 2· Numerical answer
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Answer: 48
Q572021 · 18 Mar 2021 · Shift 2· Numerical answer
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Answer: 5