Current Electricity · JEE Main previous year questions

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2024 66 questions

Q592024 · 31 Jan 2024 · Shift 1· Numerical answer
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Answer: 1
Q452024 · 31 Jan 2024 · Shift 2
The resistance per centimeter of a meter bridge wire is $r$ , with $X Ω$ resistance in left gap. Balancing length from left end is at $40 cm$ with $25Ω$ resistance in right gap. Now the wire is replaced by another wire of $2 r$ resistance per centimeter. The new balancing length for same settings will be at
1. A.10 cm
2. B.80 cm
3. C.40 cm
4. D.20 cm
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Answer: C
Q502024 · 31 Jan 2024 · Shift 2
1. A.
2. B.
3. C.
4. D.
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Answer: D
Q532024 · 31 Jan 2024 · Shift 2· Numerical answer
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Answer: 3
Q592024 · 31 Jan 2024 · Shift 2· Numerical answer
The magnetic flux $ϕ$ (in weber) linked with a closed circuit of resistance $8Ω$ varies with time (in seconds) as $ϕ = 5 t^{2} - 36 t + 1$ . The induced current in the circuit at $t = 2 s$ is ____ A.
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Answer: 2
Q332024 · 30 Jan 2024 · Shift 1
1. A. $7 V$
2. B. $44 V$
3. C. $22 V$
4. D. $15 V$
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Answer: A
Q362024 · 30 Jan 2024 · Shift 1
A series L.R circuit connected with an ac source $E = (25 sin 1000 t) V$ has a power factor of $\frac{1}{2}$ . If the source of emf is changed to $E = (20 sin 2000 t) V$ , the new power factor of the circuit will be :
1. A. $\frac{1}{3}$
2. B. $\frac{1}{2}$
3. C. $\frac{1}{5}$
4. D. $\frac{1}{7}$
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Answer: C
Q432024 · 30 Jan 2024 · Shift 1
1. A. $2 mV$
2. B. $4 V$
3. C. $0.5 V$
4. D. $12 mV$
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Answer: C
Q472024 · 30 Jan 2024 · Shift 1
An electric toaster has resistance of $60Ω$ at room temperature ( $2 7^{\circ} C$ ). The toaster is connected to a 220 V supply. If the current flowing through it reaches 2.75 A, the temperature attained by toaster is around : ( if $α = 2 \times 1 0^{- 4} /^{\circ} C$ )
1. A. $1235^{\circ} C$
2. B. $1667^{\circ} C$
3. C. $694^{\circ} C$
4. D. $1694^{\circ} C$
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Answer: D
Q522024 · 30 Jan 2024 · Shift 1· Numerical answer
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Answer: 6
Q312024 · 29 Jan 2024 · Shift 1
The resistance $R = \frac{V}{I}$ where $V = (200 \pm 5) V$ and $I = (20 \pm 0.2) A$ , the percentage error in the measurement of R is :
1. A. $5.5%$
2. B. $3%$
3. C. $7%$
4. D. $3.5%$
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Answer: D
Q342024 · 29 Jan 2024 · Shift 1
The deflection in moving coil galvanometer falls from 25 divisions to 5 divisions when a shunt of $24Ω$ is applied. The resistance of galvanometer coil will be :
1. A. $48Ω$
2. B. $100Ω$
3. C. $96Ω$
4. D. $12Ω$
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Answer: C
Q372024 · 29 Jan 2024 · Shift 1
A galvanometer having coil resistance $10Ω$ shows a full scale deflection for a current of $3 mA$ . For it to measure a current of $8 A$ , the value of the shunt should be:
1. A. $3.75 \times 1 0^{- 3} Ω$
2. B. $3 \times 1 0^{- 3} Ω$
3. C. $4.85 \times 1 0^{- 3} Ω$
4. D. $2.75 \times 1 0^{- 3} Ω$
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Answer: A
Q552024 · 29 Jan 2024 · Shift 1· Numerical answer
A square loop of side $10 cm$ and resistance $0.7Ω$ is placed vertically in east-west plane. A uniform magnetic field of $0.20 T$ is set up across the plane in north east direction. The magnetic field is decreased to zero in $1 s$ at a steady rate. Then, magnitude of induced emf is $x \times 1 0^{- 3} V$ . The value of $x$ is _______.
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Answer: 2
Q572024 · 29 Jan 2024 · Shift 1· Numerical answer
A $16Ω$ wire is bent to form a square loop. A $9 V$ battery with internal resistance $1Ω$ is connected across one of its sides. If a $4 μ F$ capacitor is connected across one of its diagonals, the energy stored by the capacitor will be $\frac{x}{2} μ J$ , where $x =$ _______.
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Answer: 81
Q322024 · 29 Jan 2024 · Shift 2
1. A. $2 A$
2. B. $1.5 A$
3. C. $1 A$
4. D. $2.5 A$
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Answer: C
Q352024 · 29 Jan 2024 · Shift 2
1. A.
2. B.
3. C.
4. D.
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Answer: B
Q432024 · 29 Jan 2024 · Shift 2
In an a.c. circuit, voltage and current are given by: $V = 100 sin (100 t) V$ and $I = 100 sin (100 t + \frac{π}{3}) mA$ respectively. The average power dissipated in one cycle is:
1. A. $5 W$
2. B. $25 W$
3. C. $2.5 W$
4. D. $10 W$
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Answer: C
Q512024 · 29 Jan 2024 · Shift 2· Numerical answer
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Answer: 30
Q372024 · 27 Jan 2024 · Shift 1
1. A.
2. B.
3. C.
4. D.
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Answer: D
Q482024 · 27 Jan 2024 · Shift 1
A wire of length $10 cm$ and radius $7 \times 1 0^{- 4} m$ is connected across the right gap of a meter bridge. When a resistance of $4.5Ω$ is connected on the left gap by using a resistance box, the balance length is found to be at $60 cm$ from the left end. If the resistivity of the wire is $R \times 1 0^{- 7} Ω m$ , then value of $R$ is :
1. A. $63$
2. B. $70$
3. C. $66$
4. D. $35$
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Answer: C
Q492024 · 27 Jan 2024 · Shift 1
A wire of resistance $R$ and length $L$ is cut into $5$ equal parts. If these parts are joined parallelly, then resultant resistance will be :
1. A. $\frac{1}{25} R$
2. B. $\frac{1}{5} R$
3. C. $25 R$
4. D. $5 R$
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Answer: A
Q342024 · 27 Jan 2024 · Shift 2
Primary side of a transformer is connected to $230 V, 50 Hz$ supply. Turns ratio of primary to secondary winding is $10 : 1$ . Load resistance connected to secondary side is $46Ω$ . The power consumed in it is :
1. A. $11.5 W$
2. B. $12.5 W$
3. C. $10.0 W$
4. D. $12.0 W$
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Answer: A
Q422024 · 27 Jan 2024 · Shift 2
1. A. $V_{1} = V_{2}$
2. B. $V_{1} \neq = V_{3} - V_{2}$
3. C. $V_{1} + V_{2} = V_{3}$
4. D. $V_{1} + V_{2} > V_{3}$
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Answer: C
Q482024 · 27 Jan 2024 · Shift 2
1. A.
2. B.
3. C.
4. D.
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Answer: A