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2022 54 questions

Q432022 · 29 Jul 2022 · Shift 1
An alternating emf $E = 440 sin 100 π t$ is applied to a circuit containing an inductance of $\frac{2}{π} H$ . If an a.c. ammeter is connected in the circuit, its reading will be :
1. A. $4.4 A$
2. B. $1.55 A$
3. C. $2.2 A$
4. D. $3.11 A$
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Answer: C
Q442022 · 29 Jul 2022 · Shift 1
A coil of inductance $1 H$ and resistance $100 Ω$ is connected to a battery of $6 V$ . Determine approximately : (a) The time elapsed before the current acquires half of its steady - state value. (b) The energy stored in the magnetic field associated with the coil at an instant $15 ms$ after the circuit is switched on. (Given $ln 2 = 0.693, e^{- 3/2} = 0.25$ )
1. A. $t = 10 ms; U = 2 mJ$
2. B. $t = 10 ms; U = 1 mJ$
3. C. $t = 7 ms; U = 1 mJ$
4. D. $t = 7 ms; U = 2 mJ$
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Answer: C
Q552022 · 29 Jul 2022 · Shift 1· Numerical answer
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Answer: 2
Q342022 · 29 Jul 2022 · Shift 2
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Alloys such as constantan and manganin are used in making standard resistance coils. Reason R: Constantan and manganin have very small value of temperature coefficient of resistance. In the light of the above statements, choose the correct answer from the options given below.
1. A.Both A and R are true and R is the correct explanation of A.
2. B.Both A and R are true but R is NOT the correct explanation of A.
3. C.A is true but R is false.
4. D.A is false but R is true.
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Answer: A
Q352022 · 29 Jul 2022 · Shift 2
A $1 m$ long wire is broken into two unequal parts X and Y. The X part of the wire is streched into another wire W. Length of $W$ is twice the length of $X$ and the resistance of W is twice that of Y. Find the ratio of length of X and Y.
1. A. $1 : 4$
2. B. $1 : 2$
3. C. $4 : 1$
4. D. $2 : 1$
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Answer: B
Q382022 · 29 Jul 2022 · Shift 2
A circuit element X when connected to an a.c. supply of peak voltage $100 V$ gives a peak current of $5 A$ which is in phase with the voltage. A second element Y when connected to the same a.c. supply also gives the same value of peak current which lags behind the voltage by $\frac{π}{2}$ . If X and Y are connected in series to the same supply, what will be the rms value of the current in ampere?
1. A. $\frac{10}{2}$
2. B. $\frac{5}{2}$
3. C. $52$
4. D. $\frac{5}{2}$
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Answer: D
Q402022 · 28 Jul 2022 · Shift 1
A wire of resistance $R_{1}$ is drawn out so that its length is increased by twice of its original length. The ratio of new resistance to original resistance is :
1. A. $9 : 1$
2. B. $1 : 9$
3. C. $4 : 1$
4. D. $3 : 1$
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Answer: A
Q532022 · 28 Jul 2022 · Shift 1· Numerical answer
The frequencies at which the current amplitude in an LCR series circuit becomes $\frac{1}{2}$ times its maximum value, are $212 rad s^{- 1}$ and $232 rad s^{- 1}$ . The value of resistance in the circuit is $R = 5 Ω$ . The self inductance in the circuit is _________ $mH$ .
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Answer: 250
Q592022 · 28 Jul 2022 · Shift 1· Numerical answer
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Answer: 780
Q412022 · 28 Jul 2022 · Shift 2
Given below are two statements : Statement I : A uniform wire of resistance $80 Ω$ is cut into four equal parts. These parts are now connected in parallel. The equivalent resistance of the combination will be $5 Ω$ . Statement II: Two resistances 2R and 3R are connected in parallel in an electric circuit. The value of thermal energy developed in 3R and 2R will be in the ratio $3 : 2$ . In the light of the above statements, choose the most appropriate answer from the option given below
1. A.Both statement I and statement II are correct
2. B.Both statement I and statement II are incorrect
3. C.Statement I is correct but statement II is incorrect
4. D.Statement I is incorrect but statement II is correct
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Answer: C
Q572022 · 28 Jul 2022 · Shift 2· Numerical answer
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Answer: 1
Q412022 · 27 Jul 2022 · Shift 1
Two sources of equal emfs are connected in series. This combination is connected to an external resistance R. The internal resistances of the two sources are $r_{1}$ and $r_{2}$ ( $r_{1} > r_{2}$ ). If the potential difference across the source of internal resistance $r_{1}$ is zero, then the value of R will be :
1. A. $r_{1} - r_{2}$
2. B. $\frac{r _{1} r _{2}}{r _{1} + r _{2}}$
3. C. $\frac{r _{1} + r _{2}}{2}$
4. D. $r_{2} - r_{1}$
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Answer: A
Q422022 · 27 Jul 2022 · Shift 1
A direct current of $4 A$ and an alternating current of peak value $4 A$ flow through resistance of $3 Ω$ and $2 Ω$ respectively. The ratio of heat produced in the two resistances in same interval of time will be :
1. A. $3 : 2$
2. B. $3 : 1$
3. C. $3 : 4$
4. D. $4 : 3$
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Answer: B
Q512022 · 27 Jul 2022 · Shift 1· Numerical answer
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Answer: 2400
Q352022 · 27 Jul 2022 · Shift 2
The velocity of the bullet becomes one third after it penetrates 4 cm in a wooden block. Assuming that bullet is facing a constant resistance during its motion in the block. The bullet stops completely after travelling at (4 + x) cm inside the block. The value of x is :
1. A.2.0
2. B.1.0
3. C.0.5
4. D.1.5
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Answer: C
Q402022 · 27 Jul 2022 · Shift 2
(A) The drift velocity of electrons decreases with the increase in the temperature of conductor. (B) The drift velocity is inversely proportional to the area of cross-section of given conductor. (C) The drift velocity does not depend on the applied potential difference to the conductor. (D) The drift velocity of electron is inversely proportional to the length of the conductor. (E) The drift velocity increases with the increase in the temperature of conductor. Choose the correct answer from the options given below :
1. A.(A) and (B) only
2. B.(A) and (D) only
3. C.(B) and (E) only
4. D.(B) and (C) only
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Answer: B
Q522022 · 27 Jul 2022 · Shift 2· Numerical answer
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Answer: 40
Q382022 · 26 Jul 2022 · Shift 1
1. A. $10 A$
2. B. $20 A$
3. C. $4 A$
4. D. $40 A$
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Answer: A
Q552022 · 26 Jul 2022 · Shift 1· Numerical answer
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Answer: 20
Q562022 · 26 Jul 2022 · Shift 1· Numerical answer
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Answer: 44
Q402022 · 25 Jul 2022 · Shift 2
1. A. $50 V$
2. B. $75 V$
3. C. $150 V$
4. D. $275 V$
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Answer: D
Q462022 · 25 Jul 2022 · Shift 2
The maximum error in the measurement of resistance, current and time for which current flows in an electrical circuit are $1%$ , $2%$ and $3%$ respectively. The maximum percentage error in the detection of the dissipated heat will be :
1. A.2
2. B.4
3. C.6
4. D.8
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Answer: D
Q552022 · 25 Jul 2022 · Shift 2· Numerical answer
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Answer: 25
Q582022 · 25 Jul 2022 · Shift 2· Numerical answer
Magnetic flux (in weber) in a closed circuit of resistance $20 Ω$ varies with time t(s) at $ϕ = 8 t^{2} - 9 t + 5$ . The magnitude of the induced current at $t = 0.25 s$ will be ___________ mA.
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Answer: 250
Q592022 · 25 Jul 2022 · Shift 2· Numerical answer
In a potentiometer arrangement, a cell of emf 1.20 V gives a balance point at 36 cm length of wire. This cell is now replaced by another cell of emf 1.80 V. The difference in balancing length of potentiometer wire in above conditions will be ___________ cm.
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Answer: 18