2018-10-01_Physics_For_You

the solenoid is decreased at a constant rate from

+2 A to –2 A in 0.05 s. Find the total charge (in PC)

owing through the coil during this time when the

resistance of the coil is 40 p^2 :.

26. A coil of inductance 0.50 H and resistance 100 :
    is connected to a 240 V, 50 Hz ac supply. Time
    lag between maximum and minimum current is
    N × 10–3 s. Find the value of N.
    Comprehension Type

In the circuit shown in gure,
the capacitor has capacitance
C = 20 PF and is initially
charged to 100 V with the
polarity shown. e resistor
R 0 has resistance 10 : At
time t = 0, the switch is closed. e smaller circuit is
not connected in any way to the larger one. e wire
of the smaller circuit has a resistance of 1.0 : m–1 and
contains 25 loops. e larger circuit is a rectangle 2.0 m
by 4.0 m, while the smaller one has dimensions a = 10.0
cm and b = 20.0 cm. e distance c is 5.0 cm (e gure
is not drawn to scale.) Both circuits are held stationary.
Assume that only the wire nearest to the smaller circuit
produces an appreciable magnetic eld through it.

27. e current (in A) in the larger circuit 200 ms aer
    closing S is
    (a) 5/e (b) 2/e (c) 15/e (d) 10/e


28. e current (in PA) in the smaller circuit 200 Ps
    aer closing S is
    (a) 54 (b) 10 (c) 15 (d) 36
    Matrix Match Type


29. A long current carrying
    wire and a loop made
    of conducting wire are
    placed in x-y plane,
    such that the long wire
    is parallel to y-axis.
    Column I is regarding
    some changes made in
    the position of loop and Column II indicates the
    resulting eects. Match the columns.
    Column I Column II
    i. If loop is moved away
    from the wire while
    keeping in x-y plane,

p. current is induced

in the loop in

anticlockwise

direction.

B

I

C

A D

y

x

ii. If loop is moved

towards the wire

while keeping in x-y

plane

q. current is induced

in the loop in

clockwise direction.

iii. If loop is rotated

about x-axis, then

just aer this

r. no emf is induced in

the loop.

iv. If loop is rotated

about y-axis, then

just aer this

s. the wire will attract

or repel the loop.

(i) (ii) (iii) (iv)

(a) p,s r,s q r

(b) q,r p,q s r,s

(c) q,s p,s r r

(d) p,r p,q p,s r

30. In series RLC circuit, R = 100 :, C=

100

π

μF,

and L=

100

π

mH are connected to an source as

shown in gure. e rms value of ac voltage is

220 V and its frequency is 50 Hz. In column I, some

physical quantities are mentioned, while in column

II, information about quantities are provided.

Match the entries of column I with the entries of

column II.

220 V, 50 Hz

R L C

Column I Column II

i. Average power dissipated

in the resistor is

p. zero

ii. Average power dissipated

in the inductor is

q. non-zero

iii. Average power dissipated

in the capacitor is

r. 163 SI units

iv. e rms voltage across

the capacitor is

s. 265.7 SI

units

(i) (ii) (iii) (iv)

(a) q,s q,r p q

(b) q,s p p q,r

(c) r p,q s r,s

(d) p,q q r,s p

b

S a

R 0

+

• C

c