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2022 54 questions

Q442022 · 30 Jun 2022 · Shift 1
An electric cable of copper has just one wire of radius $9 mm$ . Its resistance is $14 Ω$ . If this single copper wire of the cable is replaced by seven identical well insulated copper wires each of radius $3 mm$ connected in parallel, then the new resistance of the combination will be :
1. A. $9 Ω$
2. B. $18 Ω$
3. C. $28 Ω$
4. D. $126 Ω$
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Answer: B
Q582022 · 30 Jun 2022 · Shift 1· Numerical answer
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Answer: 125
Q602022 · 30 Jun 2022 · Shift 1· Numerical answer
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Answer: 2
Q412022 · 28 Jun 2022 · Shift 2
Resistance of the wire is measured as $2 Ω$ and $3 Ω$ at $1 0^{\circ} C$ and $3 0^{\circ} C$ respectively. Temperature co-efficient of resistance of the material of the wire is :
1. A. $0.033^{\circ} C^{- 1}$
2. B. $- 0.033^{\circ} C^{- 1}$
3. C. $0.011^{\circ} C^{- 1}$
4. D. $0.055^{\circ} C^{- 1}$
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Answer: A
Q522022 · 28 Jun 2022 · Shift 2· Numerical answer
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Answer: 2
Q552022 · 28 Jun 2022 · Shift 2· Numerical answer
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Answer: 8
Q362022 · 27 Jun 2022 · Shift 1
A $72 Ω$ galvanometer is shunted by a resistance of $8 Ω$ . The percentage of the total current which passes through the galvanometer is :
1. A. $0.1%$
2. B. $10%$
3. C. $25%$
4. D. $0.25%$
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Answer: B
Q412022 · 27 Jun 2022 · Shift 1
The current flowing through an ac circuit is given by $I = 5 sin (120 π t) A$ How long will the current take to reach the peak value starting from zero?
1. A. $\frac{1}{60} s$
2. B. $60 s$
3. C. $\frac{1}{120} s$
4. D. $\frac{1}{240} s$
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Answer: D
Q512022 · 27 Jun 2022 · Shift 1· Numerical answer
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Answer: 975
Q592022 · 27 Jun 2022 · Shift 1· Numerical answer
A cell, shunted by a $8 Ω$ resistance, is balanced across a potentiometer wire of length $3 m$ . The balancing length is $2 m$ when the cell is shunted by $4 Ω$ resistance. The value of internal resistance of the cell will be ____ $Ω$ .
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Answer: 8
Q572022 · 27 Jun 2022 · Shift 2· Numerical answer
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Answer: 3
Q412022 · 26 Jun 2022 · Shift 1
The magnetic flux through a coil perpendicular to its plane is varying according to the relation $ϕ = (5 t^{3} + 4 t^{2} + 2 t - 5)$ Weber. If the resistance of the coil is 5 ohm, then the induced current through the coil at t = 2 s will be,
1. A.15.6 A
2. B.16.6 A
3. C.17.6 A
4. D.18.6 A
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Answer: A
Q422022 · 26 Jun 2022 · Shift 1
An aluminium wire is stretched to make its length, 0.4% larger. The percentage change in resistance is :
1. A.0.4%
2. B.0.2%
3. C.0.8%
4. D.0.6%
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Answer: C
Q552022 · 26 Jun 2022 · Shift 1· Numerical answer
A $10 Ω$ , $20 mH$ coil carrying constant current is connected to a battery of $20 V$ through a switch. Now after switch is opened current becomes zero in $100 μ s$ . The average e.m.f. induced in the coil is ________ $V$ .
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Answer: 400
Q582022 · 26 Jun 2022 · Shift 1· Numerical answer
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Answer: 1
Q592022 · 26 Jun 2022 · Shift 1· Numerical answer
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Answer: 0
Q412022 · 26 Jun 2022 · Shift 2
1. A. $65Ω$
2. B. $20Ω$
3. C. $5Ω$
4. D. $2Ω$
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Answer: C
Q482022 · 25 Jun 2022 · Shift 1
A teacher in his physics laboratory allotted an experiment to determine the resistance (G) of a galvanometer. Students took the observations for $\frac{1}{3}$ deflection in the galvanometer. Which of the below is true for measuring value of G?
1. A. $\frac{1}{3}$ deflection method cannot be used for determining the resistance of the galvanometer.
2. B. $\frac{1}{3}$ deflection method can be used and in this case the G equals to twice the value of shunt resistances.
3. C. $\frac{1}{3}$ deflection method can be used and in this case, the G equals to three times the value of shunt resistances.
4. D. $\frac{1}{3}$ deflection method can be used and in this case the G value equals to the shunt resistances.
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Answer: B
Q562022 · 25 Jun 2022 · Shift 1· Numerical answer
A resistor develops 300 J of thermal energy in 15 s, when a current of 2 A is passed through it. If the current increases to 3 A, the energy developed in 10 s is ____________ J.
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Answer: 450
Q572022 · 25 Jun 2022 · Shift 1· Numerical answer
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Answer: 2
Q392022 · 25 Jun 2022 · Shift 2
Two cells of same emf but different internal resistances $r_{1}$ and $r_{2}$ are connected in series with a resistance R. The value of resistance R, for which the potential difference across second cell is zero, is :
1. A. $r_{2} - r_{1}$
2. B. $r_{1} - r_{2}$
3. C. $r_{1}$
4. D. $r_{2}$
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Answer: A
Q472022 · 25 Jun 2022 · Shift 2
1. A.AND gate
2. B.OR gate
3. C.NOR gate
4. D.NAND gate
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Answer: A
Q482022 · 25 Jun 2022 · Shift 2
If n represents the actual number of deflections in a converted galvanometer of resistance G and shunt resistance S. Then the total current I when its figure of merit is K will be:
1. A. $\frac{K S}{( S + G )}$
2. B. $\frac{( G + S )}{n K S}$
3. C. $\frac{n K S}{( G + S )}$
4. D. $\frac{n K ( G + S )}{S}$
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Answer: D
Q582022 · 25 Jun 2022 · Shift 2· Numerical answer
The length of a given cylindrical wire is increased to double of its original length. The percentage increase in the resistance of the wire will be ____________ %.
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Answer: 300
Q592022 · 25 Jun 2022 · Shift 2· Numerical answer
In a series LCR circuit, the inductance, capacitance and resistance are $L = 100 mH$ , $C = 100 μ F$ and $R = 10 Ω$ respectively. They are connected to an AC source of voltage $220 V$ and frequency of $50 Hz$ . The approximate value of current in the circuit will be ____ $A$ .
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Answer: 22