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OTI365 - NTSE - X Standard
NTSE SAT Physics - Current Electricity Sample Practice Questions

NTSE SAT Physics - Current Electricity

Exam Duration: 45 Mins Total Questions : 30

1 )

The resistance of a metallic wire becomes 8 times when

(a)
length is doubled
(b)
length is tripled
(c)
length is doubled and radius is halved
(d)
length is halved and radius is doubled

2 )

An electric bulb draws 1.2 A current at 6 V. The resistance of the filament of the bulb

(a)
2.5Ω
(b)
5Ω
(c)
7.2Ω
(d)
20Ω

3 )

A resistance with a resistance Ris connected to a battery with a voltage V to produce a current I. What would be the new current (in terms of I) if the voltage is doubled
and resistance is halved?

(a)
4I
(b)
I/4
(c)
2I
(d)
I/2

4 )

An electric appliance with a current of I and a resistance of R converts energy to other forms at a rate of P when connected to a 120 V outlet. What would be the new
power rating (in terms of P) if resistance is doubled (same 120 V outlet is used)?

(a)
P
(b)
2P
(c)
P/2
(d)
4P

5 )

The resultant resistance of the circuit is

(a)
0.33Ω
(b)
16Ω
(c)
3Ω
(d)
2Ω

6 )

The resistance of an electric bulb drawing 1.2A current at 6.0 V is _____

(a)
0.5W
(b)
5W
(c)
0.2W
(d)
2W

7 )

In the figure,

(a)
6W, 3 Wand 9 Ware in series
(b)
9Wand 6 Ware in parallel and the combination is in series with 3 W
(c)
3W, 6 Wand Ware in parallel
(d)
3 W, 6 Ware in parallel and 9 Wis in series

8 )

Kilowatt-hour is the unit of _______

(a)
Potential difference
(b)
Electric power
(c)
Electrical energy
(d)
Charge

9 )

When there is an electric current passing through a wire, the particles moving are ______

(a)
Electrons
(b)
Protons
(c)
Atoms
(d)
Ions

10 )

A battery is used to _____

(a)
Maintain a potential difference
(b)
Measure electric current
(c)
Measure electric potential
(d)
Safeguard against short-circuit

11 )

The unit of electrical potential is ________

(a)
ampere
(b)
coulomb
(c)
volt
(d)
watt

12 )

______ invented a simple electrochemical cell

(a)
Archimedes
(b)
Edison
(c)
Volta
(d)
Coulomb

13 )

The unit of resistance is ______

(a)
coulomb
(b)
volt
(c)
ohm
(d)
ampere

14 )

Silicon is a/an _______

(a)
conductor
(b)
insulator
(c)
semiconductor
(d)
superconductor

15 )

Ampere second could be the unit of:

(a)
Power
(b)
Conductance
(c)
Energy
(d)
Charge

16 )

Which factors will both increase the resistance of a wire in a circuit?

(a)

size of wire temperature of wire

longer lower
(b)

size of wire temperature of wire

shorter lower
(c)

size of wire temperature of wire

thicker higher
(d)

size of wire temperature of wire

thinner higher

17 )

Which circuit shows the correct positions for the fuse and the switch in the lighting circuit of a house? (Where L = live wire N = neutral wire)

18 )

A length of resistance wire is used as a resistor in a simple circuit

Four separate changes are made to the wire. Which change will not reduce the value of the resistance of the wire?

(a)
It is covered in an insulating sleeve
(b)
Its cross-sectional area is increased.
(c)
Its length is decreased.
(d)
Its temperature is decreased.

19 )

The metal case of an electric heater is earthed. The plug to the heater contains a 5 A fuse. There is a current of 4 A when the heater works normally. The cable to the heater becomes so worn that the live wire makes electrical contact with the case. What happens?

(a)
The current flows to earth and the fuse is not affected.
(b)
The fuse melts and switches off the circuit.
(c)
The metal case becomes live and dangerous
(d)
The metal case becomes very hot.

20 )

In the following circuits, heat produced in the resistor or combination of resistors connected to a 12 V battery will be

(a)
same in all the cases
(b)
minimum in case (i)
(c)
maximum in case (ii)
(d)
maximum in case (iii)

21 )

A current of 1A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly

(a)
10²⁰
(b)
10¹⁶
(c)
10¹⁸
(d)
10²³

22 )

Identify the circuit in which the electrical components have been properly connected

(a)
(i)
(b)
(ii)
(c)
(iii)
(d)
(iv)

23 )

In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 Wand 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness

(a)
Brightness of all the bulbs will be the same
(b)
Brightness of bulb A will be the maximum
(c)
Brightness of bulb B will be more than that of A
(d)
Brightness of bulb C will be less than that of B

24 )

Unit of electric power may also be expressed as

(a)
volt ampere
(b)
kilowatt hour
(c)
watt second
(d)
joule second

25 )

Number of joules in 1 kwh is

(a)
3.6 x 10⁷
(b)
3.6 x 10⁶
(c)
3.6 x 10⁵
(d)
3.6 x 10⁴

26 )

The equivalent resistance between points X and Y is 1 Ω

(a)
3Ω
(b)
1Ω
(c)
6Ω
(d)
9Ω

27 )

The resistance R of a device varies with temperature T as R = a + bT + c/T².Where a, band c are positive constant The correct representation of the variation is

28 )

The minium resistance that can be obtained using five resistors each of value 0.5 Ω.

(a)
1Ω
(b)
0.5Ω
(c)
0.2Ω
(d)
0.1Ω

29 )

An ideal voltmeter of IV has the resistance equal to

(a)
zero
(b)
infinite
(c)
unity
(d)
none of these

30 )

n equal resistors are first connected in series and then connected in parallel. What is the ratio of the resultant resistances in the two arrangements?