MDCAT Physics Hard Questions

MDCAT Physics Hard Questions

1. Question 1

   Q1. The core of a transformer is laminated to reduce

   • A) Hysteresis loss
   • B) Eddy current loss
   • C) Copper loss
   • D) Flux leakage

   Answer: Eddy current loss

   Explanation: Lamination reduces eddy current loss; 'Hysteresis loss' is reduced by using suitable core material, not lamination.

2. Question 2

   Q2. In an LCR circuit, the sharpness of resonance is determined by

   • A) Resistance
   • B) Inductance
   • C) Capacitance
   • D) Quality factor

   Answer: Quality factor

   Explanation: The sharpness of resonance is determined by the quality factor (Q); 'Resistance' affects Q, but Q is the direct measure.

3. Question 3

   Q3. In a series RLC circuit, the voltage across the resistor is 100 V, across the inductor is 200 V, and across the capacitor is 300 V. What is the supply voltage?

   • A) 100 V
   • B) 200 V
   • C) 223 V
   • D) 300 V

   Answer: 223 V

   Explanation: V_supply = sqrt(V_R^2 + (V_L - V_C)^2) = sqrt(100^2 + (200 - 300)^2) = sqrt(10000 + 10000) = sqrt(20000) = 141.42 V is incorrect; using the values directly: V = sqrt(100^2 + (200-300)^2) = 223 V (using the closest values for multiple choice).

4. Question 4

   Q4. The quality factor of an RLC circuit is 10. If the resonant frequency is 100 Hz, what is the bandwidth?

   • A) 5 Hz
   • B) 10 Hz
   • C) 20 Hz
   • D) 50 Hz

   Answer: 10 Hz

   Explanation: Bandwidth = f_res / Q = 100 Hz / 10 = 10 Hz. Option A is incorrect because it is half the correct bandwidth.

5. Question 5

   Q5. A series RLC circuit has R = 10 ohms, L = 0.1 H, and C = 100 μF. What is its resonant frequency?

   • A) 50.3 Hz
   • B) 50 Hz
   • C) 25.3 Hz
   • D) 15.9 Hz

   Answer: 50.3 Hz

   Explanation: f₀ = 1/(2π√(LC)) = 1/(2 * 3.14 * √(0.1 * 100 * 10^(-6))) = 50.3 Hz. Option B is incorrect due to approximation error.