PHY102: Electricity, Magnetism & Modern Physics TMA2

 PHY102: Electricity, Magnetism & Modern Physics TMA2

Instructions: Answer All .
After Submission, you will not be able to answer these questions

Question 1 : A single turn coil of cross-sectional area $$7.2c{m}^2$$

is in the a magnetic field of flux desity 0.45T. The field which is perpendicular to the coil, is steadily reduced to 0.0T in 5s. Calculate the induced emf.
$$0.52\mu V$$
$$0.47\mu V$$
$$0.65\mu V$$
$$0.72\mu V$$

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Question 2 : If the steady current in a wire is coming directly toward you, the magnetic field lines
circle the wire in the counterclockwise direction
circle the wire in the clocwise direction
point radially inward
point radially outward

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Question 3 : A rectangular coil of dimensions 20 cm by 15 cm lies with its plane parallel to a magnetic field of $0.5W/$m^{2}$. The coil, carrying a current of 10 A experiences a torque of 4.5 Nm in the field. How many loops has the coil?
100
20
60
30

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Question 4 : In the space surrounding a wire carrying a steady current, there exists
an oscillating magnatic field
a magnetic field pointing radially outward
no magnatic field
a magnetic field circling the wire

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Question 5 : An ammeter is suspected of giving inaccurate readings. In order to confirm the readings, the ammeter is connected to a silver votltameter in series and a steady current is passed for one hour. The ammeter reads 0.56A and 2.0124g of silver is deposited. What is the error is the ammeter reading?
1.1A
0.06A
6.0A
0.11A

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Question 6 : An electron enters a uniform magnetic field 0.20 T at an angle of ${30}^o$ the field. Determine the pitch of the helical path assuming its speed is $3\times {10}^7$ m/s
56.1 m
37.8 m
46.5 m
90.6 m

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Question 7 : In the circuit shown, each of the cells has an emf of 2V and internal resistance of $$0.1\Omega$$. Find the current in through the $0.5\Omega$ $
1.27A
3.45A
2.44A
0.13A

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Question 8 : Find the current in through the $$0.3\Omega$$ in the circuit shown
3.27A
0.69A
1.33A
2.15A

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Question 9 : For how long must a steady current of 2A flow through a copper voltameter to deposit ${10}^{-3}$kg of copper? Z for coper is 0.000329g/C
25.3min
30.2min
22.6min
42.1min

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Question 10 : An electric field of 50 kV/m is perpendicular to a magnetic field 0.25 T. What is the velocity of a charge whose initial of motion is perpendicular to both fields and which passes through the fields undeflected?
$$2\times {10}^{5}m/s$$
$$3\times {10}^{3}m/s$$
$$4\times {10}^{7}m/s$$
$$5\times {10}^{4}m/s$$

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Question 11 : A proton is accelerated through a potential difference of 100V and the enters a region in which it is moving perpendicular to a magnetic field of flux density 0.20 T. Find the radius of the circular path in which it will travel.
0.7 km
0.5 km
0.3 km
0.9 km

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Question 12 : Kirchhof's loop rule is statement of conservation of -----------
momentum
energy
mass
charge

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Question 13 : A magnetic field does not exert a force on a
moving charge
steel pin
stationary charge
magnet

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Question 14 : What is the self - inductance of an air-core solenoid, 1m long and 0.05m in diameter, if it has 1400 turns?
3.63mH
4.84mH
5.23mH
2.42mH

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Question 15 : The magnetic flux through each loop of a 35-loop coil is given by $$(3.6t-0.71t^3)\times {10}^{-2}T{m}^2$$, where the time is in seconds. Determine the induced emf at t=5.0s.
17.49V
9.17V
14.43V
6.17V

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Question 16 : A conductor 2cm long carrying a current of 8A lies at right angles to a magnetic field of which the flux density is 1.0T. Calculate the force exerted on the conductor
0.45N
0.20N
0.25N
0.16N

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Question 17 : A series circuit consisting of an uncharged $$42\mu F$$ capacitor and $$10M\Omega$$ resistor is connected to 100V power source. What are the current in the circuit and the charge on the capacitor after one time constant?
$$4.6\mu A$$ and $$221\mu C$$
$$1.3\mu A$$ and $$52\mu C$$
$$7.2\mu A$$ and $$100\mu C$$
$$3.7\mu A$$ and $$126\mu C$$

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Question 18 : A positive ion passes through an electric and magnetic fields which are mutually perpendicular. The electric field strength is 20.0kV/m while the magnetic flux density is 0.40T. At what speed will the ion pass through undeflected?
$$5.0\times {10}^{4}m/s$$
$$6.0\times {10}^{4}m/s$$
$$8.0\times {10}^{4}m/s$$
$$7.0\times {10}^{4}m/s$$

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Question 19 : A galvanometer of resistance $$120\Omega$$ a full scale deflection with a current of 0.0005A. How would you convert it to an ammeter that reads a maximum current of 5A?
connect $$2000\Omega$$ in parallel to it
connect $$200.12\Omega$$ in series to it
connect $$0.012\Omega$$ in parallel to it
connect $$20.10\Omega$$ in series to it

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Question 20 : Kirchhof's junction rule is statement of conservation of -----------
mass
energy
momentum
charge

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