Fill in the blanks:-

(1) Magnetic Flux is a ………………………………………….quantity.( scalar/ vector)

(2) Increasing flux due to outward magnetic field in a coil induces…………………………current (clockwise / anticlockwise)

(3) Decreasing flux due to inward magnetic field in a coil induce…………………………current (clockwise / anticlockwise)

(4) A loop in uniform magnetic field (direction perpendicular and into the page) is expanding in area, induced current as per Lenz’s law, will be ……………………………………… (clockwise / anticlockwise)

(5)North pole of a magnet is approaching a loop, induced current will be as seen from side of magnet ……………………………………… (clockwise / anticlockwise) and loop will behave as ……………..pole

(6)South pole of a magnet is approaching a loop, induced current will be ……… (clockwise / anticlockwise) and loop will behave as ……………..pole

(7) A magnets north pole is leaving a loop, induced current will be ……………………………………… (clockwise / anticlockwise) and loop will behave as ……………..pole

(8)South pole of a magnet is leaving a loop, induced current will be ……………………………………… (clockwise / anticlockwise) and loop will behave as ……………..pole

(9) A rectangular loop is rotating in an uniform magnetic field, its flux will be maximum when its surface will make an angle of ………………… with the field.

(10) A rectangular loop is rotating in an uniform magnetic field, its flux will be zero when its surface will make an angle of ………………… with the field.

Answers:-

Fill in the blanks:

(1) In DC, pure Inductor behaves as……………………………..

(2) In DC, capacitor behaves as……………………………..

(3)In DC, capacitor exhibit…………………………..resistance (very high/very low)

(4) Capacitive Reactance………………………………with frequency.(increases/decreases)

(5)  In case of resonance, power In an AC circuit is…………………………….( maximum /minimum)

(6) In an AC circuit voltage across capacitor ………………………………the current in it (leads/lags)

(7) In an AC circuit voltage in inductor ………………………………the current in it (leads/lags)

(8)In an AC circuit current in capacitor ………………………………the voltage across it (leads/lags)

(9) In an AC circuit current in inductor ………………………………the voltage across it (leads/lags)

(10) When a rod of soft iron in inserted in an inductor its inductance………………...(increases/decreases)

Answers:-

Fill in the blanks:

(1)Those substances which readily allow the passage of electricity through them are called…………………

(2) Those substances which offer high resistance to the passage of electricity are called…………………….

(3) Units of Charge in SI unit is……………………..

(4). Electric filed lines start on …………………..charge and end on …………………………. charge

(5) The tangent on these lines at any point gives ……………………………………….. at that point.

(6) Two point charges of same magnitude and opposite nature separated by a small distance altogether   form……………………………………………

(7) Electric Dipole Moment is a ……………………………………..quantity (vector / scalar)

(8)  Dipole is said to be in stable equilibrium in uniform electric field when angle between p and E is ……………

(9) Dipole is in unstable equilibrium when the angle between p and E is ……………

(10) Equipotential surfaces due to a system of charges…………………. intersect each other (do/ do not)

Answers:

Fill in the blanks

1.  Valence band is the energy band which includes the energy levels of the …………...... electrons
2. Conduction band is the energy band above the …………………………..band.
3. The minimum energy required for shifting electrons from ……………… band to …………………. band is called energy band gap (Eg ).
4. Pure semiconductor when doped with the suitable impurity, is known as …………..semiconductor.
5. Both type of extrinsic semiconductors (p-type and n-type) are electrically …………………(positive, negative, neutral).
6. In n-type semiconductor, majority charge carriers are …………………….. and minority charge carriers are……………..
7. In p-type semiconductor, majority charge carriers are …………………….. and minority charge carriers are……………..
8. During formation of p-n junction, due to the variation in concentration across p and n sides, holes diffuse from ………….. and electrons diffuse from ……………………….
9. Depletion region is free from ………………………………….
10. Width of depletion region is of the order of ………………m.
11. Junction diode is said to be in forward bias when the positive terminal of the external
    battery is connected …………………………………… and negative terminal to the …………………………side of the diode.
12. An ideal diode offer……………………………….resistance in forward bias.
13. An ideal diode offer……………………………….resistance in reverse bias.
14. Cut-in voltage for Si diode in forward bias is …………………..volt
15. Cut-in voltage for Ge diode in forward bias is …………………..volt
16. Band gap for Si is …………………..electron volt.
17. Band gap for Ge is …………………..electron volt.
18. ………………….diode is used as voltage regulator.

Answers:

Fill in the blanks :

1. In every atom, the positive charge and mass are densely concentrated at the centre of the atom forming its …………
2. Atomic mass unit is defined as 1/12 th of the mass of …………………..atom.
3. z  X^ A here A is …………………………
4. If R is the radius of the nucleus having mass number A, then R is proportional to  A^n where n is ……………………….
5. Density of nuclear matter is the ratio of mass of …………………………..and its…………………
6. Mass defect = mass of ……………   –       mass of ………………
7. Q value = mass defect* ………………………………………….
8. Mass defect = mass of individual nucleons – mass……………………………….
9. 1amu=……………………………………Mev
10. 1amu=……………………………………gram
11. z X^A here Z is …………………………
12. Mass of an electron in kg is………………………………………….
13. Value of 1eV in joule is……………………………
14. z X^A here A-Z is…………………..
15. Binding energy =mass defect (in amu)* …………………

1. For exothermic reaction heat is evolved that is mass defect is ………………………….

That is Q value is ……………………………………….. ( negative/positive)

1. For endothermic reaction heat is absorbed that is mass defect is …………………… that is Q value ………………………………( negative/positive)
2. BE per nucleon is BE divided by ……………………………………………………..

Fill in the blanks :

(1) If Q charge flows in time t, then current is         ……………………………..

(2) Current is a …………………………….. quantity ( scalar/vector)

(3) Current is in the direction of flow of  …………………………..charge ( positive/negative)

 (4) Current is in the opposite direction of flow of  ……………..charge ( positive/negative)

(5)  Current density is a ………………………….quantity.( scalar/vector)

(6)  Temperature coefficient for semiconductor is ……………………( positive/negative)

(7) Resistance for a conductor ………………………with temperature(increases/decreases)

(8) Resistance for a semiconductor ………………………with temperature(increases/decreases)

(9) Two silver wires with same length and different cross section. The thin wire will have ………… resistance(more/less)

(10)  Two silver wires with same thickness. The short wire will have ……………………… resistance(more/less)

Fill in the blanks

(1) Varying electric field is the source of ……………………………..

(2) Varying magnetic field is the source of ……………………………..

(3) EM wave propagates in a direction perpendicular to both …………………………..

(4). Electromagnetic waves………………..get  deflected by electric and magnetic fields. (do/do not)

 (5)  Electromagnetic waves are …………………………………in nature     (transverse/ longitudinal)

Answers:-

Fill in the blanks

1. Every atom is a sphere of radius of the order of …………………. M

2. Atom consists of small central core, called …………………………………… in which whole mass and positive charge is assumed to be concentrated.

3. Atom is electrically……………………………………….( neutral, negative, positive)

4. At a certain distance from the nucleus, whole of the KE of α-particle converts into …………………… and α-particle cannot go further close to nucleus, this distance is called distance of closest approach.

5. Bohr’s first postulate was that an electron in an atom could revolve in ……………………… without the emission of radiant energy.

6. The angular momentum (L) of the orbiting electron is quantized, i. e  mvr =......................

7. Value of h (the Planck’s constant) is………………………………………

8. SI Unit of the Planck’s constant……………………………………
9. Bohr’s third postulate states that an electron might make a transition from one of its stable orbits to another stable orbit of lower energy. When it does so,………….. is emitted having energy equal to the energy difference between the initial and final states.

10. SI Unit of Rydberg’s constant is ………………..

Answers-

यही दिन देखने को रह गए थे, पोंछा नहीं लगा सकती! भारी सामान नहीं उठा सकती !, वैभव की 65 वर्षीय माता जी ने अपनी सियाटिका दर्द के चलते डाक्टर द्वारा सुझाए परहेज़ को लेकर अपनी खिन्नता व्यक्त की।

वैभव को पहले तो यह सुनकर तकलीफ़ हुई कि अम्मा परहेज़ नहीं करना चाहती, फिर कुछ सोचकर मुस्कुराने लगे और बोले अम्मा कुछ 2-4 काम नहीं कर सकती उसका अफसोस करने के बजाय ये सोचो कि बहुत से जरूरी काम तो अभी भी कर सकती हो‌।

वैभव समझ चुके थे कि अम्मा की तकलीफ़ परहेज़ नहीं, देहभाव से जुड़ा अहंकार था, जिसे अब चोट लग रही थी क्योंकि अब उनका शरीर एक स्वस्थ व्यक्ति जैसा नहीं रहा था, जबकि शरीर तो एक साधन है और कई ऐसे महत्वपूर्ण कार्य अभी भी किए जा सकते हैं जिनमें शारीरिक रूप से पूर्ण सशक्तता आवश्यक नहीं होती।

- लवकुश कुमार

मान लें कि गर्म पानी की मात्रा इतनी ज्यादा है या उसका तापमान इतना अधिक है कि वो सारी बर्फ को पिघलाने की उर्जा रखता है |

इस मामले में दो चरण (स्टेज) होंगे पहला की “पूरी” बर्फ पहले नियत (constant) तापमान (जोकि 00 C होता है ) पर पानी में परिवर्तित हो जाये इस काम के लिए आवश्यक उर्जा होगी  

Q1 = m L; जहाँ m बर्फ का द्रव्यमान है ग्राम में और L, गलन की गुप्त ऊष्मा (Latent Heat of melting) है कैलोरी प्रति ग्राम या जूल प्रति ग्राम में ; बर्फ के लिए इसका मान होता है 80 कैलोरी प्रति ग्राम

दूसरा चरण है कि इस बर्फ के पिघलने से बने पानी के तापमान को एक कॉमन तापमान तक बढ़ाना जिसमे आवश्यक उर्जा होगी

Q2 =mst ; जहां s पानी की विशिष्ट ऊष्मा है पानी के लिए जिसका मान 1 कैलोरी / ग्राम-0C होता है, t वह कॉमन तापमान है जिस तक बीकर का पूरा पानी पहुँच जायेगा जिसमे बर्फ से बने पानी का तापमान बढ़कर और पहले से मौजूद पानी का तापमान घटकर क्योंकि पहले से मौजूद पानी द्वारा उर्जा का लॉस (नुकसान) होगा |

ली गयी ऊष्मा = दी गयी ऊष्मा

अर्थात Q1 + Q2 = m’ s (t’ - t)

जहाँ m’ पहले से मौजूद पानी का द्रव्यमान है और t’ उसका शुरुआती (बर्फ डालने से पहले ) तापमान है

इस गर्म पानी द्वारा t’ से t तक ठंडा होने में m’ s (t’ - t) उर्जा, बर्फ और उसके पानी को दी जाएगी |

नोट- दोनों तरफ द्रव्यमान का मात्रक (unit ) एकसमान रखें |

यहां ऐसा माना गया है कि न तो बीकर और न ही वातावरण कोई ऊर्जा ले/दे रहा है।