Questions
1
If a +ve charge is moved from low to high potential region,
the electric potential energy:
Answer:increases
2
Minimum number of capacitor of 2µF each required to obtain a capacitance of 5µF will be:
Answer:4
3
When a dielectric slab is introduced between the plates of a parallel plate capacitor which remains connected to a battery then charge on the plates relative to earlier charge is :
Answer:more
4
A capacitor is connected to a cell of emf E having some internal resistance r, the potential across the:
Answer:cell is E
5
Twenty seven drops of mercury are charged simultaneously to the same potential of 10 volts. What will be potential if all the charged drops are made to combine to form one large drop ?
Answer:90 V
6
Two capacitors of capacitance 6 µF and 4 µF are put in series across a 120 V battery. What is the potential difference across the 4 µF capacitor ?
Answer:72 V
8
An electron initially at rest is accelerated through a potential difference of one volt. The energy gained by electron is:
Answer:1.6 × 10-19 J
9
Two conducting spheres of radii r1 and r2 are equally charged. The ratio of their potential is
Answer:(r1r2)²
10
The capacitance of a capacitor will decrease if we introduce a slab of:
Answer:None of these
11
The dimensions of fall of potential per unit distance are given by:
Answer:[ML2T-2A-3]
12
In which of the following forms is the energy stored in a capacitor?
Answer:Electric field
14
The P.E. of an electric dipole is maximum when it makes an angle θ with electric field. The value of θ is :
Answer:π
15
The capacitance of earth, viewed as a spherical conductor of radius 6408 km is:
Answer:712 µF
16
Two capacitors of 3 µF and 6 µF are connected in series with a battery of P.d. 12 V. The P.d. across 3µF and 6µF
capacitors respectively will be :
Answer:8 V, 4 V
19
A dielectric is placed in between the two parallel plates of a capacitor as shown in the figure. The dielectric constant of the dielectric being K. If the initial capacity is C, then the new capacity will be:
A
(K + l).C
B
K.C
C
D
(k – l) C
Answer:
20
A polythene piece rubbed with wool is found to have a negative charge of 6.4 × 10-9c. How many electrons have been transferred during the process?
Answer:4 × 1010
Chapters
- Electric Charges & Fields
- Electrostatic potential and capacitance
- Electricity
- Moving charges and magnetism
- Magnetism and matter
- Electromagnetic induction
- Alternating current
- Electromagnetic waves
- Ray optics and optical instruments
- Wave optics
- Dual nature of radiation and matter
- Atoms
- Nuclei
- Semiconductor electronics
- Communication systems
