1. The voltage range of a voltmeter is given by: V = (n × k) × (RG​ + R) Where: n = 30 divisions k = 0.005 A/division (figure of merit) Rg = 20 Ω (galvanometer resistance) V = 15 volts 15 = (30 × 0.005) × (20 + R) 15 = 0.15 × (20 + R) 20 + R = 15/0.15 = 100 R = 80Ω Answer: (C) 80 Ω For more visit here:Read more

    The voltage range of a voltmeter is given by:

    V = (n × k) × (RG​ + R)
    Where:
    n = 30 divisions
    k = 0.005 A/division (figure of merit)
    Rg = 20 Ω (galvanometer resistance)

    V = 15 volts
    15 = (30 × 0.005) × (20 + R)
    15 = 0.15 × (20 + R)
    20 + R = 15/0.15 = 100
    R = 80Ω

    Answer: (C) 80 Ω

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  2. A proton moving with constant velocity implies no net force acts on it. The force on a proton due to electric and magnetic fields is given by: F =q( E + v × B) For no change in velocity, 0F =0, which is possible if: E =0 and B =0 E =0, B ≠0 (if velocity is parallel to magnetic field) Answer: (A) E =Read more

    A proton moving with constant velocity implies no net force acts on it. The force on a proton due to electric and magnetic fields is given by:

    F =q( E + v × B)
    For no change in velocity,

    0F =0, which is possible if:

    E =0 and B =0

    E =0, B ≠0
    (if velocity is parallel to magnetic field)
    Answer: (A) E = 0, B = 0

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  3. To convert a galvanometer to a voltmeter, the series resistance (R) is calculated as: V = I(Rg + R) Where: V = 10 volts I = 5 mA = 0.005 A Rg = 15Ω 10 = 0.005 × (15+R) 15 + R = 10/0.005 = 2000 R = 2000 −15 = 1985Ω Answer: (C) 1.985 × 10³ Ω For more visit here: https://www.tiwariacademy.com/ncert-solRead more

    To convert a galvanometer to a voltmeter, the series resistance (R) is calculated as:

    V = I(Rg + R)
    Where:
    V = 10 volts
    I = 5 mA = 0.005 A
    Rg = 15Ω

    10 = 0.005 × (15+R)
    15 + R = 10/0.005 = 2000
    R = 2000 −15 = 1985Ω
    Answer: (C) 1.985 × 10³ Ω

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  4. Given: Initial sensitivity = 60 divisions/ampere Final sensitivity = 10 divisions/ampere Galvanometer resistance (G) = 20 Ω The relation is: S'/S = G/G + S 10/60 = 20/20+S 1/6 = 20/20+S 20 + S = 120 ⟹ S =100Ω The shunt value is: S = G×S′/S−S′​ = 20×10/60−10 = 4Ω Answer: (C) 4 Ω For more visit here:Read more

    Given:
    Initial sensitivity = 60 divisions/ampere
    Final sensitivity = 10 divisions/ampere
    Galvanometer resistance (G) = 20 Ω
    The relation is:
    S’/S = G/G + S
    10/60 = 20/20+S
    1/6 = 20/20+S
    20 + S = 120 ⟹ S =100Ω
    The shunt value is:

    S = G×S′/S−S′​ = 20×10/60−10 = 4Ω
    Answer: (C) 4 Ω

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  5. Given: Galvanometer resistance (G) = 25 Ω Battery voltage (V) = 2 V Initial series resistance (R) = 3000 Ω Full-scale deflection = 30 units New deflection = 20 units The current sensitivity is proportional to deflection: I₂/I₁ = 20/30 = 2/3 Current through the circuit: I₁ = V/G+R = 2/3000+25 New resRead more

    Given:
    Galvanometer resistance (G) = 25 Ω
    Battery voltage (V) = 2 V
    Initial series resistance (R) = 3000 Ω
    Full-scale deflection = 30 units
    New deflection = 20 units
    The current sensitivity is proportional to deflection:
    I₂/I₁ = 20/30 = 2/3
    Current through the circuit:
    I₁ = V/G+R = 2/3000+25
    New resistance:
    I₂ = 2/G+R’
    2/3/1 = G+R/G+R’
    R’ = 4514Ω
    Answer: (A) 4514 Ω

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