Question 1 :
A metre bridge is balanced with known resistance in the right gap and a metal wire in the left gap. If the metal wire is heated the balance point<br/>
Question 2 :
Kirchhoff's law of junction, $\displaystyle \sum { I } =0$, is based on
Question 3 :
Kirchoffs law of junctions is also called the law of conservation of:<br/>
Question 4 :
In order to increase the sensitivity of a moving coil galvanometer:
Question 6 :
In a moving coil galvanometer a radial magnetic field is applied with concave magnetic poles, to have<br/>A) uniform magnetic field<br/>B) the plane of the coil parallel to field <br/>Choose the correct option among the following
Question 7 :
To increase the range of an ammeter, we need to connect a suitable<br/>
Question 8 :
In a meter bridge, a standard resistor of R ohm is connected in the left gap and two wires A and B are connected one after the other in the right gap. The balancing length measured from the left is 50 cm for either of them. If the two wires are connected is series and put in the right gap, the balancing length measured from the left would be (in cm)<br/>
Question 9 :
<span>State whether given statement is True or False<br/>The sum of all the voltage drops around a single closed loop in a circuit is zero.</span>
Question 10 :
The current that must flow through the coil of a galvanometer so as to produce a deflection of one division on its scale is called<br>
Question 11 :
A wire of length $L$ is made in the form of a coil in a moving coil galvanometer. To have maximum sensitiveness the shape of the coil is <br/>
Question 12 :
In ballistic galvanometer, the frame on which the coil is wound is non-metallic to:
Question 13 :
Wheatstones’s bridge cannot be used for measurement of very _______ resistances.<br/><br/>
Question 14 :
A lamp of 6 V and 30 W is used in a laboratory but the supply is of 120 V. what will be done to make use of the lamp?<br>(1) A resistance may be used<br>(2) A resistance may be used in series with lamp.<br>(3) The resistance should be of 18 $\Omega$.
Question 15 :
In a moving coil galvanometer, the deflection of the coil $\theta$ is related to the electric current $i$ by the relation<br>
Question 16 :
A current of $10^{-5}$ A produces a deflection of $10^{0}$ in a moving coil galvanometer. A current of $10^{-6}$ amp in the same galvanometer produces a deflection of<br><br><br>
Question 17 :
A device used for measuring small currents due to changing magnetic field is known as:
Question 18 :
Best method to increase the sensitivity of the moving coil galvanometer is to decrease<br/>
Question 19 :
<strong>If $2\%$ of the main current is to be passed through a galvanometer of resistance $G$, then resistance of the shunt required is </strong><br/>
Question 20 :
The radial magnetic field is used in a suspended coil galvanometer to provide<br>
Question 21 :
Assertion: In a meter bridge experiment, a high resistance is always connected in series with a galvanometer.
Reason: As resistance increases, current through the circuit increases.
Question 22 :
The AC voltage across a resistance can be measured using a<br>
Question 23 :
Assertion: In meter bridge experiment, a high resistance is always connected in series with a galvanometer.
Reason: As resistance increases current through the circuit increases.
Question 24 :
Which of the following material is used in making the core of a moving coil galvanometer?
Question 25 :
In a Wheatstone's bridge, there resistances P, Q and R connected in the three arms and the fourth arm is formed by two resistances $S_1$ and $S_2$ connected in parallel. The condition for bridge to be balanced will be :
Question 26 :
In a Wheatstone's bridge all the four arms have equal resistance R. If the resistance of the galvanometer is also R, the equivalent resistance of the combination across the battery is<br>
Question 27 :
In a meter bridge experiment, null point is obtained at 20 cm from one end of the wire when resistance X is balanced against another resistance Y. If $ X< Y $, then where will be the new position of the null point from the same end, if one decides to balance a resistance of 4 X against Y
Question 28 :
A cell of internal resistance $1.5 \Omega$ and of e.m.f volt balances $500\ cm$ on a potentiometer wire. If a wire of 15\ Omega$ is connected between the balance point and the cell, then the balance point will shift
Question 29 :
The area of the coil in a moving coil galvanometer is 15 $cm^{2}$ and has 20 turns. The magnetic induction is 0.2 T and the couple per unit twist of the suspended wire is $10^{-6}$ Nm per degree. If the deflection is $45^{0}$ , the current passing through it is :<br/>
Question 31 : <div>Each of Kirchoff's two laws presumes that some quantity is conserved.</div><div>Which row states Kirchhoff's first law and names the quantity that is conserved?<br></div>
Question 32 :
In metre bridge experiment, with a standard resistance in the right gap and a resistance coil dipped in water (in a beaker) in the left gap, the balancing length obtained is 'l'. If the temperature of water is increased, the new balancing length is
Question 33 :
A tangent galvanometer has a coil with $50$ turns and radius equal to $4$ cm. A current of $0.1$ Amp is passing through it. The plane of the coil is set parallel to the earth's magnetic meridian. If the value of the earth's horizontal component of the magnetic field is $7\times 10^{-5}T$ and $\mu_0= 4\pi \times 10^{-7}Wb/A-m$. then the deflection in the galvanometer needle will be :
Question 34 :
What is shape of magnet in moving coil galvanometer to make the radial magnetic field?
Question 35 :
Assertion: The coil is bound over the metallic frame in moving coil galvanometer.
Reason: The metallic frame help in making steady deflection without any oscillation.
Question 36 :
In a meter bridge, the balancing length from the left end (standard resistance of one ohm in the right gap) is found to be $20 \ cm$. The value of the unknown resistance is
Question 38 :
A galvanometer of 50 gives full scale deflection with 2 mA current as to convert it into ammeter range of 10 A is connected with it then shunt resistance will be<br/>
Question 39 :
Two identical galvanometers are taken, one is to be converted into an ammeter and other into a milliammeter. Shunt of milliammeter compared to ammeter is
Question 40 :
If in a Wheatstone bridge the battery and Galvanometer are interchanged, the condition for balance<br/>
Question 41 :
Two moving coil galvanometers 1 and 2 are with identical field magnets and suspension torque constants, but with coil of different number of turns , $ N_{1} $ and $ N_{2} $, area per turn $ A_{1} $ and $ A_{2} $ and resistance $ R_{1} $ and $ R_{2} $. When they are connected in series in the ciruit, they show deflections $ \theta _{1} $ and $ \theta _{2} $ Then $ \left ( \theta _{1}/\theta _{2} \right ) $
Question 42 :
In a Wheatstone bridge, the position of battery and galvanometer is interchanged, then the new balanced position will be
Question 43 :
A galvanometer, with a scale divided into $100$ equal divisions, has a current sensitivity of $10\;{\text{div per mA}}$ and voltage sensitivity $2{\text{ div per mV}}.$ To read $5A$ full scale deflection
Question 44 :
A potentiometer having a wire of $4$ $m$ length is connected to the terminals of a battery with a steady voltage. A leclanche cell has a null point at $1$ $m$. If the length of the potentiometer wire is increased by $1$ $m$, the position of the null point is<br/>
Question 45 :
<span>A galvanometer coil has a resistance of $150\Omega$ gives full-scale deflection for a current of $4 mA$. To convert it to an ammeter of range $0$ to $6A$ </span>
Question 46 :
In a tangent galvanometer a current of $0.1 A$ produces a deflection of $30^o$. The current required to produced a deflection of $60^o$ is
Question 47 :
In a moving coil galvanometer, the deflection ($\Phi$) on the scale by a pointer attached to the spring is
Question 48 :
Three moving coil galvanometer $A, B$ and $C$ are made of coils of three different material having torsional constant $1.8\times { 10 }^{ -8 }$, $2.8\times { 10 }^{ -8 }$ and $3.8\times { 10 }^{ -8 }$ respectively. If the three galvanometers are identical in all other respect, then in which of the above cases, current sensitivity is maximum?
Question 49 :
A moving coil ammeter requires a potential difference of $0.4V$ across it for full scale deflection. It has fixed shunt resistance of 0.01 ohm with a coil circuit resistance of $R = 1 k \ \ ohm$. The value of shunt required to give full scale deflection when the total current is $10 A$ is equal to<br/>
Question 50 :
An electron (charge $=1.6\times 10^{-19}$ coulombs) is moving in a circle of radius $5.1\times 10^{-11}m$ at a frequency of $6.8\times 10^{15}$ revolutions /sec. The equivalent current is approximately.
Question 51 :
(A) In tangent galvanometer the circular frame is rotated until the plane of the coil is parallel to magnetic meridian<br>(B) In tangent galvanometer current through it is related to deflection of needle as
Question 52 :
Assertion: A soft iron core is used in a moving coil galvanometer to increase the strength of magnetic field.
Reason: From soft iron more number of the magnetic lines of force passes.
Question 53 :
Two unknown resistances are connected in two gaps of a meter-bridge. The null point is obtained at $40\ cm$ from left end. A $30\Omega$ resistance is connected in series with the smaller of the two resistances, the null point shifts by $20\ cm$ to the right end. The value of smaller resistance in $\Omega$ is
Question 54 :
In a Wheatstone's bridge, three resistances P,Q and R are connected in three arms and the fourth arm is formed by two resistances $S_{1}$ and $S_{2}$ connected in parallel. The condition for the bridge to be balanced will be :<br/>
