Physics Test

Result

Physics Test - 6

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

If a coil of 40 turns and area 4.0 cm² is suddenly removed from a magnetic field, it is observed that a charge of 2.0 × 10^-4C flows into the coil. If the resistance of the coil is 80Ω, the magnetic flux density inWbm-2is.......

A
0.5

B
1.0

C
1.5

D
2.0

Solution

Δ q=NR Δ ϕ=NR(BA)

2* 10^-4 * 80/40×4×10^-4=1Wb m^-2
Question 2
1 / -0

Two coherent point sources S1 and S2 are separated by a small distance d as shown. The fringes obtained on the screen will be :

A
semi-circles

B
concentric circles

C
points

D
straight lines

Solution

Path difference on circles around 'P' is same. So,The fringes obtained on the screen in the given condition will beconcentric circles.

Main Concept :

Shapes of Fringes by Interference Due to Different Sources

Case I. Interference due to Two point sources in a line

(A) Screen is placed to the line joining the sources

(B) Screen is placed to the line joining the sources

Case II. Two rectangular slit source in same place (YDSE)
Question 3
1 / -0

In the circuit shown, a potential difference of 60 V is applied across AB. The potential difference between the points M and N is

A
$10 V$

B
$15 V$

C
$20 V$

D
$30 V$

Solution
Question 4
1 / -0

Two photons of same frequencies moving in same medium have

A
Same linear momentum and wavelengths

B
Same linear momentum and same speeds

C
Same energies and same linear momentum

D
None of the above

Solution

Momentum is a vector quantity. Its value depends upon magnitude as well as direction. Hence, none of the above is correct.
Main Concept :
Photon TheoryUnder the photon theory of light, a photon is a discrete bundle (or quantum) of electromagnetic (or light) energy. Photons are always in motion and, in a vacuum, have a constant speed of light to all observers, at the vacuum speed of light (more commonly just called the speed of light) of $c = 2.998 \times 10^{8} m/ s$
Other Concepts :
Concept 1 :
Momentum Of A PhotonMomentum of photon: According to the theory of Special Relativity, energy and momentum (p) of a particle with rest mass m has the following relationship: $E = m C^{2} = p \times C$ where c is the speed of light. In the case of a photon with zero rest mass,
We get,
$E = p c$
$p = \frac{h ν/}{c} = \frac{h/}{λ}$ Here $λ$ is the wavelength of the light.
Question 5
1 / -0

A heavy uniform chain lies on horizontal table top. If the coefficient of friction between the chain and the table surface is 0.25, then the maximum fraction of the length of the chain that can hang over one edge of the table is

A
20%

B
25%

C
35%

D
15%

Solution

The force of friction on the chain lying on the table should be equal to the weight of the hanging chain. Let
Question 6
1 / -0

A coil having n turns and resistance R Ω is connected with a galvanometer of resistance 4R Ω. This combination is moved magnetic field in time t so that magnetic flux changes from W1 wb to W2 wb. The induced current in the circuit is

A

B

C

D

Solution
Question 7
1 / -0

In a full wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the rectifier wave would be

A
100 Hz

B
70. 7 Hz

C
50 Hz

D
25 Hz

Solution

Frequency of full wave rectifier= 2 x input frequency = 2 x 50 = 100 Hz.
Question 8
1 / -0

If the resistivity of an alloy is ρ′ and that of constituent metal is ρ then

A

B

C

D
There is no simple relation between $ρ$ and $ρ^{'}$

Solution
Question 9
1 / -0

A circular disc of radius 0.2 meter is placed in a uniform magnetic field of induction $\frac{1/}{π} Wb m^{}$ ⁻² in such a way that its axis makes an angle of 60^o with $\underset{B}{\to}$ .The magnetic flux linked with the disc is

A
0.08 Wb

B
0.01 Wb

C
0.02 Wb

D
0.06 Wb

Solution
Question 10
1 / -0

Two bodies of identical mass m are moving with constant velocity v but in the opposite directions and stick to each other, the velocity of the compound body after collision is

A
v

B
2v

C
Zero

D
$\frac{v}{2}$

Solution