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WorksheetsPHYSICS TEST 4 (TUESDAY)
Total questions: 40
Worksheet time: 33mins
In photo-emission, the number of photo-electrons ejected per second depends on the?
frequency of the beam
work function of the metal
threshold frequency of the metal
intensity of the beam
If electron are accelerated from rest through a potential difference of 10kv, what is the wavelength of the associated electron?
[m = 9.1 x 10-31 kg, e = 1.6 x 10-19 C, h = 6.6 x 10-34 Js]
1.22 x 10-11m
3.87 x 10-10m
2.27 x 1011m
2.27 x 1014m
The ground stated energy for the hydrogen atom is 5.44 x 10-19. If an electron drops from zero energy to ground state, calculate the frequency of the emitted radiation?
[h = 6.6 x 10-34 Js]
5.0 x 1016 Hz
2.0 x 1016 Hz
5.0 x 1015 Hz
2.0 x 1015 Hz
No correct option
Which of the following statements is TRUE of photoelectric effect?
it cannot occur in liquids
the energy of the emitted electrons is independent of the work function of the surface
the energy of the emitted electron depends on the wavelength of the incident light
the greater the intensity of the incident light, the greater the energy of the emitted electron
Photometer is used to measure
Kinetic energy of liberated electrons
Intensity of light
frequency of light
wavelength of light
Calculate the energy of the third level of an atom if the ground state energy is -24.8 eV
-9.20 eV
-8.20 eV
-2.75 eV
-1.75 eV
A bar magnet is divided into two pieces, which of the following statement is correct?
two new magnets are created
the magnetic field of each separate piece becomes stronger
the electric field is created
the bar magnet is demagnetized
A magnet relay is a device used for?
reading the magnitude of magnetic flux
controlling another circuit carrying larger current
turning in sports
storing magnetic field
The device for measuring the angle of dip is
Dip circle
Dip inclination
Dip variation
Dip meter
A closed coil of wire is placed near a magnet. The magnet lies along the axis of the coil. Under which of the following conditions would there be no current in the coil?
When the coil is moved towards the stationary magnet
When the coil is moved away from the stationary magnet
When the coil is held stationary but the magnet is moved towards the coil
When both the coil and magnet are held stationary
When the coil is held stationary but the magnet is moved away from the coil
Which of the following CANNOT be used to produce a steel magnet? The
Passing of an electric current through a solenoid
Repeated stroking of the specimen with a magnet
Repeated stroking of the specimen in opposite directions with magnets
Heating of the specimen
Hammering of the specimen in the earth's magnetic field
The angle of declination in a place is 10°E. Calculate the true geographic bearing if the compass reads N40°E
N40°E
N50°E
N25°E
N30°E
A circuit has an area of 0.4 m2 and consists of 50 loops of wire. If the loops are twisted and allowed to rotate at a constant angular velocity of 10 rads-1 in a uniform magnetic field of 0.4 T, What is the amplitude of the induced voltage?
8 V
10 V
20 V
80 V
Calculate the magnetic force on an electron in a magnetic field of flux density 10 T, with a velocity of 3 x 107 m/s at 60º to the magnetic field (e = 1.6 x 10-19 C)
4.8 x 10-11 N
4.6 x 10-12 N
4.16 x 10-11 N
4.3 x 10-11 N
If the radius of the earth is 6.4 x 106 m, the escape velocity of a satellite from the earth is?
[g = 10 ms-2]
1.13 x 104 ms-1
9.00 x 103 ms-1
8.00 x 103 ms-1
1.27 x 104 ms-1
The value of x, y and z respectively in the expression MxLyTz for the universal gravitational constant G are?
2, -3, -2
-1, 3, -2
-1, 2, -3
-2, -1, 3
An object is weighed at different locations on the Earth. What will be the right observation?
Both the mass and weight vary
The weight is constant while the mass varies
The mass is constant while the weight varies
Both the mass and weight are constant
The gravitational pull on the moon is 1/6 that of the earth. If a body weighs 6.0 N on the moon, what will be the weight on the earth?
6.0 N
5.0 N
12.0 N
36.0 N
The gravitational force between two objects masses 1024 kg and 1027 kg is 6.67N. Calculate the distance between them [ G = 6.6 x 10-11 Nm2kg-2 ]
1.0 x 1020 m
2.0 x 10-20 m
1.0 x 10-20 m
2.0 x 1020 m
A planet has mass m1 and is at a distance r1 from the sun. A second planet has mass
m2 = 10m1 and is at a distance of r2 = 2r1 from the sun. Determine the ratio of the gravitational force experienced by the planets
1:5
2:5
3:5
4:5
Four cells each of e.m.f 1.5V and internal resistance of 4Ω are connected in parallel. What is the effective e.m.f. and internal resistance of the combination?
6.0V, 16Ω
6.0V, 1Ω
1.5V, 4Ω
1.5V, 1Ω
An electric generator has e.m.f. of 240 V and an internal resistance of 1Ω if the current supplied by the generator is 20A when the terminal voltage is 220 V, find the ratio of the power supplied to the power dissipated?
11:1
1:11
12:11
11:12
A galvanometer with full-scale deflection of 10 mA is to be converted to a voltmeter with full-scale deflection of 5v. if a series resistance of 498Ω is used for the conversion, the resistance of the galvanometer is ?
1 Ω
2 Ω
5 Ω
10 Ω
Three capacitors of capacitance 2μF, 4μFand 8μF are connected in parallel and a P.D of 6V is maintained across each capacitor, the total energy stored is?
2.52 x 10-6J
6.90 x 10-6J
2.52 x 10-4J
6.90 x 10-4J
A current of 0.5 A flows through a resistor when connected to a 40 V battery. How much energy is dispatched in 2 minutes?
2400 J
9600 J
1500 J
1200 J
A 35 kΩ is connected in series with a resistance of 40 kΩ. What resistance R must be connected in parallel with the combination so that the equivalent resistance is equal to 25 kΩ?
40 kΩ
37.5 kΩ
45.5 kΩ
30 kΩ
When a charged ebonite rod is brought near a charged glass rod, there will be
attraction
repulsion
spark
no force experienced
A parallel plate capacitor separated by an air gap is made of 0.8m2 tin plates and 20 mm apart. It is connected to 120 V battery. What is the charge on each plate?
Take ε0 = 8.85 × 10-12 Fm-1
3.54 nC
42.5 nC
35.4 nC
4.25 nC
The charge of magnitude 1.6 x 10-19 C is placed in a uniform electric field of intensity
1200 Vm-1. Calculate its acceleration, if the mass of the charge is 9.1 x 10-31 kg
2.11 x 1014 ms-2
2.11 x 1013 ms-2
1.20 x 1014 ms-2
1.20 x 1013 ms-2
Calculate the value of electric field intensity due to a charge of 4μC if the force due to the charge is 8N
2.0 x 106 NC-1
3.0 x 106 NC-1
4.0 x 106 NC-1
8.0 x 106 NC-1
The surface temperature of a swimming pool on a warm day is 25ºC and the temperature at the bottom is 15ºC. If the swimming pool has a surface area of 620 m2 and a depth of 1.5m. Find the rate at which energy is transferred by conduction from the surface to the bottom of the swimming pool.
[Thermal conductivity of water (k) = 0.6071 Wm-1K-1]
2.5 kW
250 kW
300 kW
3.0 kW
If the S.V.P of water vapour was 13.5mmHg at 33ºC and 7.3mmHg at 7ºC. Find the percentage relative of the air on a day when average air temperature was 33ºC and dew point was 7ºC.
55%
60%
54%
51%
Newton's law of cooling is valid only for a
small temperature range
large temperature range
free flow range
presence of heat source
The lower and upper fixed points marked on a mercury-in-glass thermometer are 210 mm apart. The end of the mercury column in the tube is 49 mm above the lower fixed point in a room. What is the temperature of the room in degree celcius?
55.3 °C
23.3 °C
49.0 °C
16.1 °C
The expansion of solids can be considered a disadvantage in the?
Balance wheel of a watch
Fitting of wheels on rims
Fire alarm
Thermostat
A platinum resistance thermometer has a resistance of 4 Ω at 0°C and 10 Ω at 100°C. Assuming the resistance changes uniformly with temperature, Calculate the resistance of the thermometer when the temperature is 45°C
14.0 Ω
6.7 Ω
3.4 Ω
2.7 Ω
A piano wire 50 cm long has a total mass of 10 g and its stretched with a tension of 800 N. Find the frequency of the wire when it sounds its third overtone note.
800 Hz
600 Hz
400 Hz
200 Hz
The pitch of a musical note is determined by the frequency of the sound wave that it produces. If two instruments have the same frequency, which of the following factors will most affect the difference in their pitches?
The shape of the instrument
The tension of the string
The size of the instrument
The material of the instrument
Two tuning forks of frequencies 6Hz and 4Hz respectively are sounded together. The beat frequency is
2 Hz
5 Hz
8 Hz
10 Hz
What is the least possible error encountered when taking measurement with a metre rule?
1.1 mm
0.5 mm
0.2 mm
0.1 mm
