MCQs of Current Electricity

Current Electricity MCQs

MCQs of Current Electricity

Showing 101 to 110 out of 119 Questions

101.

Resistivity of a wire is

ρ

. Its length is 4 m and resistance is 4

Ω

. The volume of this wire is _____

m^{3}

(a)	$\sqrt{\frac{4}{ρ}}$
(b)	$4 ρ$
(c)	$\frac{ρ}{4}$
(d)	$\sqrt{4 ρ}$

102.

Power of two bulbs operating on same voltage are P₁ and P₂. If these bulbs are connected in series to the same operating voltage, then the total power consumed is _____.

(a)	$\sqrt{p_{1} p_{2}}$
(b)	$p_{1} + p_{2}$
(c)	$\frac{p_{1} + p_{2}}{p_{1} p_{2}}$
(d)	$\frac{p_{1} p_{2}}{p_{1} + p_{2}}$

103.

Given quantity of water is boiled by an electric heater in 5 min. If supply voltage of heater reduces to half, then time taken to boil same quantity of water will be _____ min. (Assume resistance of heater remaining constant)

(a)	10
(b)	20
(c)	40
(d)	2·5

104.

Electric charge passing through a resistor changes with time t as Q = at - bt². Then the time in which maximum charge passes through resistor R = _____.

(a)	$\frac{a}{2 b}$
(b)	$\frac{2 b}{a}$
(c)	$\frac{a^{2}}{2 b^{2}}$
(d)	$\frac{a^{3}}{b}$

105.

n identical bulbs operating on same voltage are available. When all such bulbs are connected in series to the same operating voltage source, then consumed in each bulb = _____W.

(a)	nP
(b)	P
(c)	$\frac{P}{n}$
(d)	$\frac{P}{n^{2}}$

106.

Two batteries each of emf 2 V and internal resistance 1

Ω

are connected in series to a resistor R. Maximum possible power consumed by the resistor = _____.

(a)	$3 \cdot 2 W$
(b)	$\frac{16}{9} W$
(c)	$\frac{8}{9} W$
(d)	$2 W$

107.

Two bulbs, each of 40 watt, are connected in series. power consumed by this connection is _____.

(a)	20 watt
(b)	100 watt
(c)	40 watt
(d)	60 watt

108.

σ_{1,} σ_{2}

and

σ_{3}

are conductance

(σ = \frac{1}{R})

of three conductors of same dimensions, then their equivalent conductance when they are joined in series, will be _____.

(a)	$σ_{1} + σ_{2} + σ_{3}$
(b)	${\frac{1}{σ}}_{1} + {\frac{1}{σ}}_{2} + {\frac{1}{σ}}_{3}$
(c)	$\frac{σ_{1} σ_{2} σ_{3}}{σ_{1} + σ_{2} + σ_{3}}$
(d)	None of the above

109.

Formula for current flowing through a wire is I = 6t² + 4t - 2. Here, t is in second and I is in ampere. In this wire, what is the quantity of electric charge passing in time interval 1 sec to 2 sec ?

(a) 8 C

(b) 18 C

(c) 20 C

(d) 24 C

110.

When

R_{1}

and

R_{2}

resistance are connected in parallel,equivalent resistance obtained is

\frac{6}{5}

Ω

. If

R_{1}

= 2

Ω

R_{2}

= _____

Ω

(a)	$\frac{3}{5}$
(b)	$\frac{4}{5}$
(c)	$\frac{1}{3}$
(d)	$3$

Showing 101 to 110 out of 119 Questions