Try to solve these questions on your own in my net post I'll publish 3 marks and 5 marks sample questions.
Question 1. W cm apart on a hat is the amount of work done in moving 100 nC charge between two points 5 cm apart on an equipotential surface? 1
Question 2. What is the value of refractive index of medium of polarising angle 60 degree? 1
Question 3. State two factors on which temperature of inversion of a thermocouple may depend. 1
Question 4. In which direction would a compass needle align if taken to geographic (i) north and (ii) south pole? 1
Question 5. The instantaneous voltage from an a.c. source is given by E=300 sin 314t . What is the r.m.s. voltage of the source? 1
Question 6. Compare the radii of two nuclei with mass number 1 and 27 respectively. 1
Question 7. How does energy gap in an intrinsic semiconductor vary, when doped with a pentavalent impurity. 1
Question 8. If the temperature of good conductor increases, how does the relaxation time of electrons in the conductor change. 1
Question 9. Draw a labelled ray digram shwing the formation of image using a Newtonian type reflecting telescope. 2
Question 10. The output voltage of an ideal transformer, connected to a 240 V a.c. is 24 V. When transformer is used to light a bulb with rating 24 V , 24 W, calculate the current in the primary coil of the circuit. 2
Question 11. Can magnetic field set a resting electron into motion. 2
Question 12. You are given two niclei 3X7 and 3Y4. Are they isotopes of same element? State the resion . Which one of the two nuclei is likely to be more stable. 2
Question 13. A heater coil is rated 100 W , 200 V. It is cut into two identical parts. Both parts are connected togather in parallel , to the same source of 200 V. Calculate the energy librated per second in new combination. 2
Question 14. A charge q moving in a straight line is accelerated by potential difference V. It enters uniform magnetic field B perpandicular to its path . Deduce in terms of V an expression for the radius of circular path in which it travels. 2
Question 15. State the reason for the following observations recorded from the surface of the moon:
(i) sky appears dark
(ii) rainbow is never formed.
Question 16. Write any three characterstics , a ferromagnetic substance should posess , if it is to be used to make a permanent magnet. Give one example of such material. 2
Question 17. The value of ground state of hydrogen atom is -13.6 eV.
(i) What does the negative sign signify.
(ii) how much energy is required to take an electron in this atom from ground state to the first exited state. 2
Question 1. Why electron capture is common in case of heavy nucleus?
Answer. A heavy nucleus has large positive charge. Moreover, the raidus of K-shell in heavy nuclei is much smaller than that in case of light nucleus. Due to both these factors, the K-shell electrons experiences a large force of attraction due to positive nucleus and is keptured by it.
Question 2. Why is nuclear fusion difficult to carry out?
Answer. The fusion reaction require very high temperature condition and it has to be obtained by causing explosion due to fission process. Further , due to very high temperature no material can sustain the region where fusion is to be carried out.
Question 3. Would you prefer to use a transistor in CB or CE as a amplifier?
Answer. Transistor in CE configuration as an amplifier as curent gain in this case is more than that as in case of amplifier in CB configuration.
Question 4. Explain why the core of the transformer is laminated?
Answer. The core of a transformer is laminated so as to reduce loss of energy due to eddy currents. The magnitude of the eddy currents set up is considerably minimised, when the core is laminated.
Question 5. Why is the core of a transformer made of a magnetic material of high permeability?
Answer. The transformer works on the principle of mutual induction. In case, the core has a high value of magnetic permeability, the magnetic field lines will crowd through the core and the magnetic flux linkage between the two coils will also be large.
Question 6. When the motor of an electric refrigerator starts, the lights in the house become dim momentarily. Why?
Answer. When the electric motor of the refrigerator starts, it draws maximum current from the a.c. mains. It is because, just at the start of the motor, the back e.m.f. is zero. Due to the large current drawn by the motor, the current through the lights (connected in parallel) decreases and they become dim. However, as the armature of the motor rotates, back e.m.f. is produced and the motor draws current less than that drawn in the beginning . Then, the lights recover their brilliance.
Qiestion 1
If relatibe permeability of iron is 5500 then its magnetic susceptibility is
(a) 5500 x 107
(b) 5501
(c) 5499
(d) 5500 x 10-7
Question 2
An atom is paramagnetic if it has
(a) an electric dipole moment
(b) no magnetic moment
(c) a magnetic moment
(d) no electric dipole moment
Question 3
Magnetic moment of a diamegnetic atim is
(a) 0
(b) infinity
(c) negative
(d) positive
Question 4
Mark the correct statement(s)
(a) When a particle moves under uniform circular motion its acceleration is constant
(b) Under the influence of uniform circular motion , instantaneous acceleration is perpandicular to the tangential velocity
(c) Under the influence of non-uniform circular motion , instantaneous acceleration is perpandicular to the tangential velocity
(d) All the above
Qiestion 5
In a meter bridge apparatus , the bridge wire should have
(a) high resistivity and low temperature coefficent
(b) high resistivity and high temperature coefficent
(c) low resistivity and high temperature coefficent
(d) low resistivity and low temperature coefficent
Question 6
Mark out the correct statement
(a) Image formed by convex mirror can be real
(b) Image formed by convex mirror can be virtual
(c) Image formed by convex mirror can be magnified
(d) Image formed by convex mirror can be inverted
Answer
1. c
2. c
3. a
4. b .... When a particle moves under the influence of uniform circular motion magnitude of acceleration is always constant but direction of acceleration keeps changing, it always remains towards the centre . So acceleration is always perpandicular to the the tangential velocity in this case.
5. a
6. a,b,c,d
Question 1. W cm apart on a hat is the amount of work done in moving 100 nC charge between two points 5 cm apart on an equipotential surface? 1
Question 2. What is the value of refractive index of medium of polarising angle 60 degree? 1
Question 3. State two factors on which temperature of inversion of a thermocouple may depend. 1
Question 4. In which direction would a compass needle align if taken to geographic (i) north and (ii) south pole? 1
Question 5. The instantaneous voltage from an a.c. source is given by E=300 sin 314t . What is the r.m.s. voltage of the source? 1
Question 6. Compare the radii of two nuclei with mass number 1 and 27 respectively. 1
Question 7. How does energy gap in an intrinsic semiconductor vary, when doped with a pentavalent impurity. 1
Question 8. If the temperature of good conductor increases, how does the relaxation time of electrons in the conductor change. 1
Question 9. Draw a labelled ray digram shwing the formation of image using a Newtonian type reflecting telescope. 2
Question 10. The output voltage of an ideal transformer, connected to a 240 V a.c. is 24 V. When transformer is used to light a bulb with rating 24 V , 24 W, calculate the current in the primary coil of the circuit. 2
Question 11. Can magnetic field set a resting electron into motion. 2
Question 12. You are given two niclei 3X7 and 3Y4. Are they isotopes of same element? State the resion . Which one of the two nuclei is likely to be more stable. 2
Question 13. A heater coil is rated 100 W , 200 V. It is cut into two identical parts. Both parts are connected togather in parallel , to the same source of 200 V. Calculate the energy librated per second in new combination. 2
Question 14. A charge q moving in a straight line is accelerated by potential difference V. It enters uniform magnetic field B perpandicular to its path . Deduce in terms of V an expression for the radius of circular path in which it travels. 2
Question 15. State the reason for the following observations recorded from the surface of the moon:
(i) sky appears dark
(ii) rainbow is never formed.
Question 16. Write any three characterstics , a ferromagnetic substance should posess , if it is to be used to make a permanent magnet. Give one example of such material. 2
Question 17. The value of ground state of hydrogen atom is -13.6 eV.
(i) What does the negative sign signify.
(ii) how much energy is required to take an electron in this atom from ground state to the first exited state. 2
Question 1. Why electron capture is common in case of heavy nucleus?
Answer. A heavy nucleus has large positive charge. Moreover, the raidus of K-shell in heavy nuclei is much smaller than that in case of light nucleus. Due to both these factors, the K-shell electrons experiences a large force of attraction due to positive nucleus and is keptured by it.
Question 2. Why is nuclear fusion difficult to carry out?
Answer. The fusion reaction require very high temperature condition and it has to be obtained by causing explosion due to fission process. Further , due to very high temperature no material can sustain the region where fusion is to be carried out.
Question 3. Would you prefer to use a transistor in CB or CE as a amplifier?
Answer. Transistor in CE configuration as an amplifier as curent gain in this case is more than that as in case of amplifier in CB configuration.
Question 4. Explain why the core of the transformer is laminated?
Answer. The core of a transformer is laminated so as to reduce loss of energy due to eddy currents. The magnitude of the eddy currents set up is considerably minimised, when the core is laminated.
Question 5. Why is the core of a transformer made of a magnetic material of high permeability?
Answer. The transformer works on the principle of mutual induction. In case, the core has a high value of magnetic permeability, the magnetic field lines will crowd through the core and the magnetic flux linkage between the two coils will also be large.
Question 6. When the motor of an electric refrigerator starts, the lights in the house become dim momentarily. Why?
Answer. When the electric motor of the refrigerator starts, it draws maximum current from the a.c. mains. It is because, just at the start of the motor, the back e.m.f. is zero. Due to the large current drawn by the motor, the current through the lights (connected in parallel) decreases and they become dim. However, as the armature of the motor rotates, back e.m.f. is produced and the motor draws current less than that drawn in the beginning . Then, the lights recover their brilliance.
Qiestion 1
If relatibe permeability of iron is 5500 then its magnetic susceptibility is
(a) 5500 x 107
(b) 5501
(c) 5499
(d) 5500 x 10-7
Question 2
An atom is paramagnetic if it has
(a) an electric dipole moment
(b) no magnetic moment
(c) a magnetic moment
(d) no electric dipole moment
Question 3
Magnetic moment of a diamegnetic atim is
(a) 0
(b) infinity
(c) negative
(d) positive
Question 4
Mark the correct statement(s)
(a) When a particle moves under uniform circular motion its acceleration is constant
(b) Under the influence of uniform circular motion , instantaneous acceleration is perpandicular to the tangential velocity
(c) Under the influence of non-uniform circular motion , instantaneous acceleration is perpandicular to the tangential velocity
(d) All the above
Qiestion 5
In a meter bridge apparatus , the bridge wire should have
(a) high resistivity and low temperature coefficent
(b) high resistivity and high temperature coefficent
(c) low resistivity and high temperature coefficent
(d) low resistivity and low temperature coefficent
Question 6
Mark out the correct statement
(a) Image formed by convex mirror can be real
(b) Image formed by convex mirror can be virtual
(c) Image formed by convex mirror can be magnified
(d) Image formed by convex mirror can be inverted
Answer
1. c
2. c
3. a
4. b .... When a particle moves under the influence of uniform circular motion magnitude of acceleration is always constant but direction of acceleration keeps changing, it always remains towards the centre . So acceleration is always perpandicular to the the tangential velocity in this case.
5. a
6. a,b,c,d
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