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WorksheetsPhysics 2nd Half Syllabus Test
Total questions: 40
Worksheet time: 3600secs
A parallel plate condenser has uniform electric field E(V/m) in the space between the plates. if the distance between the plates is d(m) and area of each plate is A(m2) the energy (joules) stored in the condenser is.
E2Ad / ε0
ε0EAd
½ (ε0 E2)
½ ( ε0 E2 Ad)
When hydrogen atom is in its first excited level its radius is.
Four times its ground state radius
Same
Twice
Three times
In the nth orbit, the energy of an electron En=n213.6eV for hydrogen atom. The energy required to take the electron from first orbit to second orbit will be
3.4 eV
10.2 eV
12.1 eV
13.6 eV
Energy of electron in a orbit of H-atom is
Positive
Negative
Zero
Nothing can be said
X-rays of λ=1A° have frequency
3×108Hz
3×1018Hz
3×1010Hz
3×1015Hz
How is the potential within and on the surface of a conductor?
Indirectly proportional
Directly proportional
Zero
Constant
The diagram shows the electric field lines in a region of space containing two small
charged spheres (Y and Z). Then
Y is negative and Z is positive
The magnitude of the electric field is the same everywhere
The electric field is strongest midway between Y and Z
The electric field is not zero anywhere (except infinitely far from the spheres)
A cell of emf 5V and internal resistance 1 Ω will give maximum power output to
A single resistor of 1 Ω
Two 1 Ω resistor connected in series
Two 1 Ω resistor connected in parallel
None of these
A charged particle enters a magnetic field such that the direction of initial velocity is different from the direction of the field. Which of the following characteristics of the particle will not change with time?
Momentum
Acceleration
Kinetic energy
Direction of motion
Figures show some equipotential lines distributed in space. A charged object is moved from point A to point B.
The work done in Fig. (i) is the greatest.
The work done in Fig. (ii) is least.
The work done is the same in Fig. (i), Fig.(ii) and Fig. (iii).
The work done in Fig. (iii) is greater than Fig. (ii) but equal to that in Fig. (i).
An induced emf is produced when a magnet is plugged into a coil. The magnitude of the induced emf is independent of
The strength of the magnet
The resistivity of the wire of the coil
The speed with which the magnet is moved
The number of turns in the coil
A conductor of length 1m carrying current of 1A is placed parallel to a magnetic field of 1 Gauss. The magnetic force acting on the conductor is
Zero
1 newton
10–4 newton
1 Dyne
From a metal surface violet light causes photo emission but blue do not. If sodium light is used then photo electrons
Not emitted
Are emitted with less K.E
Are emitted with zero K.E
Are emitted with very high K.E
Stopping potential is high for
High intensity of light
Good conducting metal surface
High frequency of light
Insulators metal surface
The cesium coated oxidized silver emits electrons for
Infrared light
U.V light
Visible light
Valence shell
The current in the circuit is 4.8 A. What is the rate of flow and the direction of flow of electrons through the resistor R?
3.0 × 1019 s–1 in direction X to Y
3.0 × 1019 s–1 in direction Y to X
6.0 × 1018 s–1 in direction X to Y
6.0 × 1018 s–1 in direction Y to X
A proton is traveling due north. If a uniform magnetic field is applied vertically down then the particle :
a) deflected towards west b) revolves in anti clock wise direction
c) acquires acceleration d) comes to rest
b, c, d are correct
a & b are correct
a, b & c are correct
a & c are correct
The angular momentum of the electron in the 2nd Bohr orbit is
h
πh
2πh
4πh
If a charge particle is placed one by one at point A, B and C then at which point it will experience a larger force.
At point “A”
At point ‘B”
At point “C”
None of these
If the wavelength is brought down from 6000 °A to 4000 °A in a photoelectric experiment, then what will happen ?
The work function of the metal will increase
The threshold frequency will decrease
No change will take place
Cut off voltage will increase
If 2 bodies are oppositely charged with 400µC and 200µC, the distance between them in the air is 0.5 m. The force between the bodies should be
1850 N
2880 N
3000 N
3250 N
Find capacitance across AB:
C/3
3C
C
None of these
If two bulbs are connected in parallel and one bulb blows out, what happens to the other bulb?
The other bulb blows out as well
The other bulb glows with increased brightness
The other bulb continues to glow with the same brightness
The other bulb stops glowing
A cylindrical conductor of length L and uniform area of cross-section A has resistance R. Another conductor of length 2L and resistance R of the same material has area of cross-section
A/2
2A
3A/2
3A
When the wires are connected in parallel, the heat produced in the thinner wire is
H1 and that in the thicker wire is H2 Then:
H1 = H2
H1 > H2
H1 < H2
H1 ≥ H2
Calculate the energy in the 5 ohm resistor in 20 seconds.
21.5kJ
2.15J
2.15kJ
21.5J
Two radioactive sources A and B initially contain equal number of radioactive atoms. Source A has a half-life of 1 hour and source B has a half-life of 2 hours. At the end of 2 hours, the ratio of the rate of disintegration of A to that of B is
1:2
2:1
4:1
1:1
The masses of three copper wires are in ratio 1:3:5 and their lengths are in ratio 5:3:1. What is the ratio of their resistance?
1:3:5
5:3:1
125:15:1
25:9:1
Which of the following correctly describes the magnetic field near a long straight wire?
The field consists of straight lines perpendicular to the wire
The field consists of straight lines parallel to the wire
The field consists of radial lines originating from the wire
The field consists of concentric circles centered on the wire
The strength of electromagnet can be increased by introducing a soft iron core
Outside the coil
Inside the coil
Round the coil
Above the coil
For a cell, the graph between the potential difference (V) across the terminals of the cell and the current (I) drawn from the cell is shown in the figure.
The e.m.f. and the internal resistance of the cell are
2V, 0.5 Ω
> 2V, 0.5 Ω
2V, 0.4 Ω
> 2V, 0.4 Ω
An E.M.F. can be induced by _________
Change in the magnetic field only
Change in the area of cross section only
Change in angle between magnetic field and area only
Change in the magnetic field, area or angle between them
The ripple factor indicates the number of ripples in the
A.C output
D.C output
A.C input
None of these
A __________ is used in the circuit to reduce the ripple factor
Resistor
Capacitor
Inductor
Diode
A component that allows only unidirectional current to pass through is
Resistor
Diode
Transformer
Inductor
Higher value of decay constant indicates _______
faster decay
higher half life
slower decay
both B & C
The force on a stationary charge at any point inside the current carrying loop is:
Zero
Infinite
Dependent on current
Dependent on shape of loop
If the angular speed of rotation of an armature of alternating current generator is
doubled, then the induced electromotive force will be:
Half
Twice
Four times
No change
Equipotential planes are
Non-parallel to one another
Circular
Parallel to one another
Intersecting
Temperature coefficient of resistance (α) is equal to
RoΔtRt+Ro
RoΔtRo−Rt
RoΔtRt−Ro
Rt−RoRoΔt
