Photon Academy Of Science 04 (Unit 1 Whole)

1. In India frequency of AC is

50Hz

70Hz

30Hz

90Hz

2. Amount of work done in bringing a unit positive charge from infinity to point in an electric field is termed as

Potential

Electric field

Electric dipole

Electric flux

3. One Joule per coulomb is called?

Volt

Newton

Fairad

Ohm

4. What is si unit of capacitance

Fairad

C/v

N/c

Ohm

5. In domestic wiring we use which type of combination

Paralle

Series

Mixed

Simple

6. What is real form of First principle of electric current

I = neAvd

I=q/t

I= v/R

I= RA/L

7. If two capacitors of lOμF each are connected in parallel, their equivalent capacitance will be?

20 microfairad

10 micrifairad

30 miceofairad

15 microfairad

8. A, B and C are three points in a uniform electric field. The electric potential is [NEET 2013]

At A

At B

At C

At all A B and C

9. Which one do you like?

A =q B=r C= s. D= p

A=p B=q C=r D= s

A=s B= r C=q D=p

A=r B=p.C=q D=s

10. A capacitor stores 0.24 coulombs at 10 volts. Its capacitance is

0.024f

24f

240f

0.240f

11. In the electric field due to a point charge q, a test charge is carried from A to the points B, C, D and E lying on the same circle around q. The work done is

Zero along any one of the paths AB, AD, AC and AE

Least along AB

Least along BC

Least along AE

12. Calculate the equivalent capacitance between the points a and b.

3c/4

4/3c

C/4

3c

13. A dielectric slab which is responsible for increasing capacitance is

Polar

Non polar

Both polar and non polar

Insulator

14. Coulomb's force between 2 point charges 10µC and 5µC placed at a distance of 150cm is

0.2N

0.5N

5N

4N

15. What would be energy supplied by charge if a point charge of +2 is transferred from a point at potential 100V to a point at potential 50V?

100J

10J

1000J

0J

16. A charge 'Q' is placed at the centre of a hemispherical surface of radius 'R'. The flux of electric field due to charge 'Q', through the surface of hemisphere is

Q/2εo

I/2q

Q/4εo

2Q/εo

17. Which one will be show maximum value of resistivity

Metal

Non metal

Alloy

Semi conductor

18. Name the event when a metal losses their resistivity at a definite point of temperature is called

Superconductivity

Resistance

Resistivity

Mobility

19. If 2 bodies are oppositely charged with 400µC and 200µC, distance between them in air is 0.5 m. force between bodies should be

2880N

2800N

1300N

1440N

20. A dielectric K = 2 is inserted between the plates of a 20μF capacitor. It capacitance will become In

20μF

40

60

10

21. The electric field intensity at a point situated 4 meters from a point charge is 200 N/C. If the distance is reduced to 2 meters, the field intensity will be

800N/C

400N/c

200N/C

100N/c

22. An electric dipole is placed at an angle of 30° with an electric field intensity 2 m 105 N/C. It experiences a torque equal to 4 N m. The charge on the dipole, if the dipole length is 2 cm, is [NEET 2016]

8mC

2mC

5mC

7mC

23. The force between two charges is 120 N. If the distance between the charges is doubled, the force will be

30N

20N

40N

240N

24. If positively charged pendulum is oscillating in a uniform electric field as shown in figure. Its time period as compared to that when it was uncharged:

Will increase

No change

Will decrease

Will doubled

25. If the static electric force is 144 N, what is the distance between both charges… (1μC = 10^-6C and k = 9.10⁹ N.m².C^-2)

5cm

4cm

3cm

9cm

26. Electric charge q , q and -2q are placed at the corners of an equilateral triangle ABC of side L. The magnitude of electric dipole moment of the system is

(√3)qL

Ql

2qL

5qL

27. A combination of capacitors is set up as shown in the figure. The magnitude of the electric field, due to a point charge Q (having a charge equal to the sum of the charges on the 4 μF and 9 μF capacitors), at a point distant 30 m from it, would equal : [JEE Main 2016]

360N/C

420N/C

480N/C

240N/C

28. Three concentric metallic spherical shells of radii R, 2R, 3R, are given charges Q1, Q2, Q3, respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells, Q1 : Q2 : Q3, is [IIT JEE 2009]

1 : 2 : 3

1:3:5

1:4:9

1:8:18

29. If we increase length of any conductor wire 10% then what is new value of resistance

20%

21%

15.5%

30%

30. What is the value of flux for one face of cube

Φ=q/£•

1/6 q/£•

Q/l

Side x side

31. The figure is a plot of lines of force due to two charges q1 and q2. Find out the sign of charges

Both are positive

Both are negative

Both are neutral for each other

Can't expressable