1. What is the near and far point of
a normal eye?
2. Name the component of eye that is
responsible for the adjustment of eyelens?
3. To an astronaut why does the sky
appear dark instead of blue?
4. Why the star twinkle but not
earth?
5. Draw the labelled diagram of
human eye and explain the image formation?
6. What is power of accommodation?
How ciliary muscles helps in accommodation?
7. Explain the function of
a. Iris
b. Pupil
c. Retina
8. Calculate the number of electrons
constituting one coulomb of charge.
9. Define the unit of current.
10.
What is meant by
saying that the potential difference between two points is 1 V?
11.
The potential
difference between the terminals of an electric heater is 60 V when it draws a
current of 4 A from the source. What current will the heater draw if the
potential difference is increased to 120 V?
12.
A wire of given
material having length l and area of cross-section A has a
resistance of 4. What would be the resistance of
another wire of the same material having length l/2 and area of
cross-section 2A?
13.
Why are coils of
electric toasters and electric irons made of an alloy rather than a pure metal?
14.
An electric lamp,
whose resistance is 20 Ω, and a conductor of 4 resistance are connected to a 6 V
battery Calculate (a) the total resistance of the circuit, (b) the current
through the circuit, and (c) the potential difference across the electric lamp
and conductor.
15.
In the circuit
diagram given in Fig. 12.10, suppose the resistors R1, R2 and R3 have
the values respectively, which have
been connected to a battery of 12 V. Calculate (a) the current through each
resistor, (b) the total current in the circuit, and (c) the total circuit
resistance.
16.
What are the
advantages of connecting electrical devices in parallel with the battery
instead of connecting them in series?
17.
What is (a) the
highest, (b) the lowest total resistance that can be secured by combinations of
four coils of resistance ?
18.
An electric iron of
resistance takes a current of 5 A. Calculate
the heat developed in 30 s.
19.
An electric
refrigerator rated 400 W operates 8 hour/day. What is the cost of the energy to
operate it for 30 days at Rs 3.00 per kW h?
20.
How many resistors (in parallel) are
required to carry 5 A on a 220 V line?
21.
Compare the power
used in the resistor in each of the
following circuits: (i) a 6 V battery in series with and resistors, and (ii) a 4 V
battery in parallel with and resistors.
22.
An electric heater of
resistance 8 draws 15 A from the service mains
2 hours. Calculate the rate at which heat is developed in the heater.
23.
Why is the series
arrangement not used for domestic circuits?
24.
A current through a
horizontal power line flows in east to west direction. What is the direction of
magnetic field at a point directly below it and at a point directly above it?
25.
List the properties
of magnetic lines of force.
26.
Why don’t two
magnetic lines of force intersect each other?
27.
Choose the correct
option.The magnetic field inside a long straight solenoid-carrying current
a. is zero.
b. decreases as we move towards its
end.
c. increases as we move towards its
end.
d. is the same at all points.
28.
State Fleming’s
left-hand rule.
29.
What is the role of
the split ring in an electric motor?
30.
Explain different
ways to induce current in a coil.
No comments:
Post a Comment
add your Idea.........