# Q&A - Ask Doubts and Get Answers

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Engineering
12 Views   |   4 days, 6 hours ago

Let where       Then   equals :

• Option 1)

• Option 2)

• Option 3)

• Option 4)

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V vakul.arora
Answered 22 hours, 12 minutes ago

Use this Double Sin Formula

Engineering
6 Views   |   3 weeks, 4 days ago

Question

From a sphere of mass M and radius R, a  smaller sphere of radius  is carved out such that the cavity made in the original sphere is between its centre and the periphery. (See figure). For the configuration in the figure where the distance between the centre of the original sphere and the removed sphere is 3R, the gravitational force between the two spheres is :

Question

From a sphere of mass M and radius R, a  smaller sphere of radius  is carved out such that the cavity made in the original sphere is between its centre and the periphery. (See figure). For the configuration in the figure where the distance between the centre of the original sphere and the removed sphere is 3R, the gravitational force between the two spheres is :

Engineering
53 Views   |   3 weeks, 6 days ago

Let ABC be a triangle whose circumcentre is at P.  If the position vectors of A, B, C

and P are

respectively, then the position vector of the orthocentre of this triangle, is :

• Option 1)

• Option 2)

• Option 3)

• Option 4)

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A Anurag Uikey
Answered 2 weeks, 4 days ago
Engineering
56 Views   |   3 weeks, 6 days ago

If (10)9 + 2(11)1   (10)8 + 3(11)2  (10)7 +......  +10 (11)9 = k (10)9, then k is equal to :

• Option 1)

100

• Option 2)

110

• Option 3)

• Option 4)

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S solutionqc
Answered 3 weeks, 5 days ago
Use Sum of n terms of a GP -   - wherein first term common ratio number of terms        and   (10)9 + 2(11)1 (10)8 + 3(11)2 (10)7 +......  +10 (11)9 = k(10)9 Take common 109    Subtract   Option 1) 100 Option 2) 110 Option 3) Option 4)
Engineering
62 Views   |   1 month ago

In a large building, there are 15 bulbs of   40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW.  The voltage of the electric mains is 220 V.  The minimum capacity of the main fuse of the building will be :

• Option 1)

8 A

• Option 2)

10 A

• Option 3)

12 A

• Option 4)

14 A

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S solutionqc
Answered 1 month ago
As we have learned In parallel Grouping - -    Resistance of each bulb of 40 W    Resistance of 15 bulbs = 1210/15 = 242/3  Resistance of 100 W bulb =    Resistance of 5 such bulbs = 485/5  Resistance of fan =     =  605  Resistance of 5 such fan  = 605 /5  = 121 Resistance of heater =   Equivalent resistance  R = 484 / 25                  Option 1) 8 A Option 2) 10 A Option 3) 12...
Engineering
43 Views   |   1 month ago

In the circuit shown, current (in A) through the 50 V and 30 V batteries are, respectively :

• Option 1)

2.5 and 3

• Option 2)

3.5 and 2

• Option 3)

4.5 and 1

• Option 4)

3  and 2.5

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S solutionqc
Answered 1 month ago
As we discussed in Cell - The device which converts Chemical energy into electrical energy is known as electric cell. Option 1)    2.5 and 3 Option 2) 3.5 and 2 Option 3) 4.5 and 1 Option 4)   3  and 2.5
Engineering
42 Views   |   1 month ago

A d.c. main supply of e.m.f. 220 V is connected across a storage battery of e.m.f. 200 V through a resistance of 1. The battery terminals are connected to an external resistance ‘R’. The minimum value of ‘R’, so that a current passes through the battery to charge it is :

• Option 1)

• Option 2)

• Option 3)

• Option 4)

zero

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S solutionqc
Answered 1 month ago
Option 1) Option 2) Option 3) Option 4) zero
Engineering
111 Views   |   2 months ago

In the circuit shown, the current in the 1 resistor is :

• Option 1)

1.3 A ,from P to Q

• Option 2)

0 A

• Option 3)

0.13 A ,from Q to P

• Option 4)

0.13 A ,from P to Q

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V vishal dange
Answered 1 month, 2 weeks ago

answer is option 3)0.13A from Q  to P

•  Let, Current i1 from 6v battery passes through 3 ohm resistance . At Q current breaks and current i2 goes through 3 ohm and ( i1-i2 ) goes through 1 ohm ,.
• Applying, kirchoffs law in 1st and 2nd loop,we get two eqns as follows
• 4i1-i2=6
• 6i2-i1=9
• solving ,,  i1-i2 =0.13 A
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Engineering
83 Views   |   2 months ago

In the electric network shown, when no current flows through the resistor in the arm EB, the potential difference between the points A and D will be :

• Option 1)

3V

• Option 2)

4V

• Option 3)

5V

• Option 4)

6V

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S safeer
Answered 1 month ago

$-4+3+V_{cd}+0=0$

$V_{cd}=1 Volt$

$\therefore V_{A}-V_{D}=9-3-1=5V$

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Engineering
74 Views   |   2 months ago

The supply voltage to a room is 120 V. The resistance of the lead wires is 6 . A 60 W bulb is already switched on. What is the decrease of voltage across the bulb, when a 240 W heater is switched on in parallel to the bulb?

• Option 1)

10.04 Volt

• Option 2)

Zero Volt

• Option 3)

2.9 Volt

• Option 4)

13.3 Volt

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
77 Views   |   2 months ago

If and be the threshold wavelength and wavelength of incident light, the velocity of photoelectron ejected from the metal surface is :

• Option 1)

• Option 2)

• Option 3)

• Option 4)

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
72 Views   |   2 months ago

Chloro compound of Vanadium has only spin magnetic moment of 1.73 BM.  This Vanadium chloride has the formula :

(at. no. of V=23)

• Option 1)

VCl2

• Option 2)

VCl4

• Option 3)

VCl3

• Option 4)

VCl5

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
63 Views   |   2 months ago

Resistance of a given wire is obtained  by measuring the current flowing in it and the voltage difference applied across it. If the percentage errors in the measurement of the current and the voltage difference are 3% each, then error in the value of resistance of the wire is

• Option 1)

6%

• Option 2)

zero

• Option 3)

1%

• Option 4)

3%

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
65 Views   |   2 months ago

This question has Statement I and Statement II. Of the four choices given after the Statements, choose the one that best describes the two Statemens.

Statement - I : Higher the range, greater is the resistance of ammeter.

Statement - II : To increase the range of ammeter,additional shunt needs to be used across it.

• Option 1)

Statement - I is false, Statement - II is true.

• Option 2)

Statement - I is true, Statement - II is true, Statement - II is the correct explanation of Statement - I.

• Option 3)

Statement - I is true, Statement - II is true, Statement - II is not the correct explanation of Statement - I.

• Option 4)

Statement - I is true, Statement - II is false.

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
76 Views   |   2 months ago

A 10 V battery with internal resistance and a 15V battery with internal resistance are connected in parallel to a voltmeter (see figure). The reading in the voltmeter will be close to :

• Option 1)

11.9 V

• Option 2)

12.5 V

• Option 3)

13.1 V

• Option 4)

24.5 V

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
27 Views   |   2 months ago

A 3 olt battery with  negligible internal resistance is connected in a circuit as shown in the figure. The current I i n the circuit will be

• Option 1)

• Option 2)

• Option 3)

• Option 4)

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
32 Views   |   2 months ago

Two electric bulbs marked  25 W-220 V and 100 W - 220 V are connected in series to a 440 V supply .Which of the bulbs will fuse?

• Option 1)

both

• Option 2)

100W

• Option 3)

25 W

• Option 4)

neither

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
175 Views   |   2 months, 2 weeks ago

Three capacitances, each of 3 F, are  provided. These cannot be combined to provide the resultant capacitance of :

• Option 1)

• Option 2)

• Option 3)

• Option 4)

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
95 Views   |   2 months, 2 weeks ago

The magnitude of the average electric field normally present in the atmosphere just above the surface of the Earth is about

150 N/C, directed inward towards the center of the Earth.  This gives the total net surface charge carried by the Earth to  be:

• Option 1)

+670 kC

• Option 2)

- 670 kC

• Option 3)

- 680 kC

• Option 4)

+ 680 kC

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N Neha Gupta
Answered 1 month, 2 weeks ago
Engineering
188 Views   |   2 months, 2 weeks ago

In the given circuit diagram when the current reaches steady state in the circuit, the charge on the capacitor of capacitance C will be :

• Option 1)

• Option 2)

• Option 3)

• Option 4)

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N Neha Gupta
Answered 1 month, 2 weeks ago
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