Current Electricity Test

Result

Current Electricity Test - 69

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

The resistance across A and B is

A
$$\dfrac {R} {2}$$

B
$$R$$

C
$$\dfrac {6R} {5}$$

D
$$4R$$

Solution

The resistances in upper branch are a series combination of $$R$$ and $$2R$$
So their series resistance is $$R_1=R+2R=3R$$

The resistances in lower branch are a series combination of $$R$$ and $$R$$
So their series resistance is $$R_2=R+R=2R$$

Now $$3R$$ and $$2R$$ are in parallel.

$$\dfrac{1}{R_{eq}}=\dfrac{1}{2R}+\dfrac{1}{3R}=\dfrac{5}{6R}$$
$$\therefore R_{eq}=\dfrac{6R}{5}$$.
Question 2
1 / -0

All of the following can induce an emf in a coil of wire EXCEPT

A
moving a magnet through the coil

B
placing a stationary coil of wire in an increasing magnetic field

C
Placing a stationary coil of wire in a stationary magnetic field.

D
Placing a stationary coil of wire in a decreasing magnetic field.

Solution
Question 3
1 / -0

The resistance of a wire at roan temperature $$30^oC$$ is found' to be $$10\Omega$$ Now to increase the resistance by $$10\Omega$$, the temperature of the wire must. be [The temperature coefficient of resistance of die material of the wire is 0.002

A
$$36^oC$$

B
$$86^oC$$

C
$$560^oC$$

D
$$33^oC$$

Solution

$$R = {R_0}\left( {1 + \alpha \theta } \right)$$
$$10 = {R_0}\left( {1 + \alpha {{30}^0}} \right)$$
$$10 + 10 = {R_0}\left( {1 + \alpha \theta } \right)$$
$$\frac{{10}}{{20}} = \frac{{1 + 0.002 \times 30}}{{1 + 0.002 \times \theta }}$$
$$ \Rightarrow 1 + 0.002\theta = 2 + 0.12$$
$$ \Rightarrow 0.002\theta = 1 + 0.12$$
$$\theta = \frac{{1.12}}{{0.002}}$$
$$\theta = {560^0}C$$
Hence,
option $$(C)$$ is correct answer.
Question 4
1 / -0

At what moment when the potentiometer is balanced ,

A
Current flows only in the primary circuit.

B
Current flows only in the secondary circuit.

C
current flows in both primary and secondary circuits .

D
current doesnot flow in any circuit

Solution

At the balanced condition of potentiometer, potential difference across secondary circuit is equal to the EMF of battery of secondary circuit, so there is no current in secondary circuit, but primary circuit work as it is. so current only flows in primary circuit.
Question 5
1 / -0

For circuit shown, the value of emf of battery 'E' is.

A
15 V.

B
8 v

C
200v/7

D
65v/7.

Solution
Question 6
1 / -0

In which of the cases no emf is induced in conducting wire?

A
open circuit

B
conductor at rest

C
L perpendicular to B and v

D
None of the above

Solution

EMF is inducted due to flux change in coil when coil rotate. If coil will not rotate magnetic flux link to the coil will not change Hence, emf will not be induced Therefore, correct option is B.
Question 7
1 / -0

In a meter bridge setup, which of the following should be the properties of the one meter long wire?

A
High resistivity and low temperature coefficient

B
Low resistivity and low temperature coefficient

C
Low resistivity and high temperature coefficient

D
High resistivity and high temperature coefficient

Solution
Question 8
1 / -0

Six identical cells, each of emf of $$6V$$, are connected in parallel. The net emf across the battery is

A
$$6V$$

B
$$36V$$

C
$$0V$$

D
Between $$6V$$ and $$36V$$

Solution
Question 9
1 / -0

Kirchoff's voltage law and current law are respectively in accordance with the conservation of

A
Charge and momentum

B
Charge and energy

C
Energy and charge

D
Energy and momentum

Solution
Question 10
1 / -0

When the switch $$S$$, in the circuit shown, is closed, then the value of current $$i$$ will be :

A
$$3A$$

B
$$5A$$

C
$$4A$$

D
$$2A$$

Solution

Let voltage at $$C = xv$$
$$KCL : i_1 + i_2 = i$$
$$\dfrac{20-x}{2} + \dfrac{10-x}{4} = \dfrac{x-0}{2}$$
$$\Rightarrow x = 10$$
and $$i = 5Amp$$.