Electricity Test

Result

Electricity Test - 9

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 process of acquiring temporary electrification under the influence of a charged body is called

A
attraction

B
induction

C
repulsion

D
conduction

Solution

The process of acquiring temporary electrification under the influence of a charged body is called induction.In Induction , the positive and the negative charge of the body gets separated under the influence of the another charged body.
Question 2
1 / -0

A current of 4.8 A is flowing through a conductor. The number of electrons passing per second through the conductor is

A
3 10¹⁹

B
76.8 10²⁰

C
7.68 10²⁰

D
3 10²⁰

Solution

I = ne/t
4.8 = n × 1.6 × 10^-19/1
n = 3 × 10¹⁹
Question 3
1 / -0

Ohm's law gives a relation between

A
resistance of a conductor and its inductance

B
capacity of a conductor and its charge

C
the current flowing through a circuit and the potential difference across it

D
None of these

Solution

Ohm's law gives a relation between the current flowing through a circuit and the potential difference across it.
Question 4
1 / -0

When the diameter of a wire is doubled, its resistance becomes

A
half

B
double

C
one-fourth

D
one-eighth

Solution

, where The resistance of wire is inversly propotional to the square of the diameter.So,resistance will be one-fourth
Question 5
1 / -0

The resistance of a wire of uniform diameter D and length L is R. The resistance of another wire of the same material, but diameter 2D and length 4L will be

A
2R

B
R

C
R/2

D
R/4

Solution

R =

The new resistance will be R'.

R' =
Question 6
1 / -0

^{_{Two resistances are joined in parallel, whose resultant is (6/5)}_{. One of the resistance wires is broken and the effective resistance is 2}_{. The resistance of the broken wire is}}

A
^_3/5

B
^_6/15

C
^₂

D
^₃

Solution

R_eq = 6/5 ohmR₁ = 2 ohmR₂ = ? R₂ = 3 ohm
Question 7
1 / -0

The effective resistance of the network between points A and B is

A
^₆

B
^₂

C
^₁

D
zero

Solution

1/R = 1/6 + 1/6 + 1/6 = 3/6 = 1/2
R = 2 ohm
Question 8
1 / -0

A battery and resistances are connected in a circuit as follows. The current flowing through the ammeter A is

A
1 ampere from B to C

B
1 ampere from C to B

C
zero

D
(25/16) ampere

Solution

As the bridge is a balanced bridge so the current in the circuit will be zero.
Question 9
1 / -0

Three wires of resistances 18 ohms, 15 ohms and 10 ohms are connected in parallel. The current in the 18 ohm wire is 0.75 A. What is the current in the 15 ohm wire?

A
0.6 A

B
0.9 A

C
1.2 A

D
1.8 A

Solution

V = IR

Voltage across 18 ohm resistance:

V = 18 x 0.75 = 13.5 V

As the resistances are in parallel, the voltage across each resistance will be the same.

Current through the 15 ohm resistance is:
Question 10
1 / -0

A geyser of 2.5 kW is connected to a battery of 220 volts. An iron of 1.5 kW is also connected to the battery. To prevent any failure of fuse, the fuse wire must have a current rating of

A
15 A

B
7 A

C
20 A

D
6 A

Solution

We know: P = VI
For geyser, Current I₁ = 2500/220
For iron, I₂ = 1500/220
I₂ = 6.8 A
Total current = I₁ + I₂ = 18.16 A
So, the fuse wire must be of a rating more than 18.16 A.
From all the options given, 20 A is the only rating more than 18.16 A. Hence, it is the answer.
Question 11
1 / -0

The north pole of a magnet is brought near a stationary positively charged conductor. The north pole exerts a force, which will

A
attract the conductor

B
try to repel

C
not affect the conductor at all

D
repel the north pole itself

Solution

The north pole of a magnet is brought near a stationary positively charged conductor. The north pole exerts a force, which will not affect the conductor at all
Question 12
1 / -0

A cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis, then

A
current will be induced in the coil

B
no current will be induced in the coil

C
both emf and current will be induced in the coil

D
None of the above

Solution

As the magnetic flux linked with the coil is not changing, so no emf will be induced. An induced emf is zero. So, the current in the coil will be zero.
Question 13
1 / -0

A transformer is used

A
to transform electric energy into mechanical energy

B
to obtain suitable dc voltage

C
to transform ac into dc

D
to obtain suitable ac voltage

Solution

A transformer is used to obtain suitable ac voltage
Question 14
1 / -0

A milliammeter of range 10 mA gives full-scale deflection for a current of 100 mA when a shunt of 0.1 Ω is connected in parallel to it. The coil of the milliammeter has a resistance of

A
0.9 Ω

B
1 Ω

C
1.1 Ω

D
0.11 Ω

Solution

Let's consider the given milliammeter.

Given data:
I_m = 10 mA
I = 100 mA
R_sh = 0.1 Ω
From the above figure, current through shunt resistor R_sh,
I_sh = I - I_m = (100 - 10) mA = 90 mA

From the above figure,
Question 15
1 / -0

The direction of magnetic field at a point due to an infinitely long wire carrying current is

A
parallel to the current

B
anti-parallel to the current

C
along the perpendicular drawn from a point on the wire

D
perpendicular to the plane containing the conductor and the point

Solution

The direction of magnetic field at a point due to an infinitely long wire carrying current is perpendicular to the plane containing the conductor and the point
Question 16
1 / -0

Charge Q is divided into two parts, which are then kept some distance apart. The force between them will be the highest, if the two parts are

A
Q/2 each

B
Q/4 and 3Q/4

C
Q/3 and 2Q/3

D
e and (Q–e)

Solution

Charge Q is divided into two parts, which are then kept some distance apart. The force between them will be the highest, if the two parts are Q/2 each.The charge will be equally divided.
Question 17
1 / -0

Power is transmitted from a power house on high voltage AC because

A
the rate of transmission is faster at high voltage

B
it is more economical due to less power wastage

C
the life of the current carrying wire is prolonged

D
of precaution against the theft of transmission - line

Solution

Power is transmitted from a power house on high voltage AC because it is more economical due to less power wastage
Question 18
1 / -0

DC can be converted into AC with the help of

A
rectifier

B
regulator

C
transformer

D
inverter

Solution

DC can be converted into AC with the help of inverter
Question 19
1 / -0

Molten sodium chloride conducts electricity due to the presence of

A
free electrons

B
free ions

C
free molecules

D
free atoms of Na and Cl

Solution

Molten sodium chloride conducts electricity due to the presence of free ions.
Question 20
1 / -0

A small piece of unmagnetised substance gets repelled when it is brought near a powerful magnet. The substance can be

A
paramagnetic

B
ferromagnetic

C
non – magnetic

D
diamagnetic

Solution

A small piece of unmagnetised substance gets repelled when it is brought near a powerful magnet. The substance can be diamagnetic